Transmission management system, transmission system, program for transmission management system and computer readable information recording medium

ABSTRACT

A transmission management system, when content data is communicated among plural transmission terminals via a communication network, selects a relay apparatus which relays the content data. The system determines whether first attributes of the respective plural transmission terminals are the same; determines whether second attributes of the respective plural transmission terminals are the same; and selects a first relay apparatus in a case where the first attributes are determined to be the same, selects a second relay apparatus in a case where the first attributes are not determined to be the same but the second attributes are determined to be the same, and selects a third relay apparatus in a case where the first attributes are not determined to be the same and the second attributes are not determined to be the same.

TECHNICAL FIELD

The present invention relates to a transmission management system bywhich when content data is communicated using a communication networkamong plural communication terminals, a relay apparatus which relays thecontent data is selected.

BACKGROUND ART

Along with a recent tendency of reducing business trip costs andbusiness trip man hours, transmission systems for carrying out a TVconference using a communication network such as the Internet havebecome wide spread. In such a transmission system, when a telephone callis carried out between plural transmission terminals, image data andvoice data are transmitted therebetween, and thus, a TV conference canbe carried out.

Further, thanks to recent expansion of the broadband environment,transmission of image data with high image quality and voice data withhigh sound quality becomes possible. Thereby, a situation of anotherperson in a TV conference becomes able to be easily understood, and itbecomes possible to understand each other by conversation at a highlevel.

In such a TV conference system, in order to relay content data among TVconference terminals, a relay apparatus is provided in general. In thiscase, it is known to select a relay apparatus from among plural relayapparatuses depending on attributes of the TV conference terminalsparticipating in the TV conference, for the purpose of load sharing in acommunication network or such. For example, it is known that aconference room ID (identification) is allocated to a TV conferenceterminal, and a relay apparatus is selected based on the conference IDof the TV conference terminal participating in the TV conference (seeJapanese Laid-Open Patent Application No. 2006-229416). Thereby, it ispossible to average traffic in relay apparatuses, and thus, it ispossible to share the load of the communication network to a certainextent.

However, in the above-mentioned TV conference system according to therelated art, although it is possible to select a relay apparatus basedon the conference ID of the TV conference terminal, it may not bepossible to select an optimum relay apparatus depending on pluralindependent attributes such as a communication network to which the TVconference terminal is connected, an area in which respectivetransmission terminals are connected with a communication network, andso forth.

SUMMARY OF INVENTION

According to an embodiment of the present invention, there is atransmission management system which, when content data is communicatedamong plural transmission terminals via a communication network, selectsa relay apparatus which relays the content data. The transmissionmanagement system includes a first attribute determination partconfigured to determine whether first attributes of the respectivetransmission terminals are the same; a second attribute determinationpart configured to determine whether second attributes of the respectivetransmission terminals are the same; and a selection part configured toselect a first relay apparatus in a case where the first attributedetermination part has determined that the first attributes are thesame, select a second relay apparatus in a case where the firstattribute determination part has determined that the first attributesare not the same but the second attribute determination part hasdetermined that the second attributes are the same, and select a thirdrelay apparatus in a case where the first attribute determination parthas determined that the first attributes are not the same and the secondattribute determination part has determined that the second attributesare not the same.

Other objects, features and advantages of the present invention willbecome more apparent from the following detailed description when readin conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1A generally shows one example of a transmission system accordingto an embodiment of the present invention;

FIG. 1B generally shows another example of the transmission systemaccording to the embodiment of the present invention;

FIG. 2 shows an external appearance in one example of a transmissionterminal according to the embodiment;

FIG. 3 shows a hardware configuration of the transmission terminalaccording to the embodiment;

FIG. 4 shows a hardware configuration common to a transmissionmanagement system, a relay apparatus, a program providing system and amaintenance system according to the embodiment;

FIG. 5 is a functional block diagram common to the terminal, theapparatus and the system included in the transmission system accordingto the embodiment;

FIG. 6 is a functional block diagram showing details of a relayapparatus selection part 56 shown in FIG. 5;

FIG. 7 shows a concept of a change quality management table;

FIG. 8A illustrates a concept of image quality of image data (lowresolution);

FIG. 8B illustrates a concept of image quality of image data (mediumresolution);

FIG. 8C illustrates a concept of image quality of image data (highresolution);

FIG. 9 shows a concept of a relay apparatus management table;

FIG. 10 shows a concept of a terminal authentication management table;

FIG. 11 shows a concept of a terminal management table;

FIG. 12 shows a concept of a destination list management table;

FIG. 13 shows a session management table;

FIG. 14 shows a quality management table;

FIG. 15 shows an attribute management table;

FIG. 16 is a sequence diagram showing a process of managing stateinformation indicating an operating state of each relay apparatus;

FIG. 17 is a general view showing a state where image data, voice dataand various sorts of management information are transmitted in thetransmission system;

FIG. 18 is a sequence diagram showing a process in a preparation stepfor starting a telephone call between transmission terminals;

FIG. 19 is a sequence diagram showing a process of selecting a relayapparatus;

FIG. 20 is a flowchart showing a process of selecting a relay apparatus;

FIG. 21 shows a concept of a destination list according to theembodiment;

FIG. 22 is a sequence diagram showing a process of requestingparticipation in an image and voice data session;

FIG. 23 is a flowchart showing a process of selecting a relay apparatus;

FIG. 24 is a sequence diagram showing a process of transmitting imagedata and voice data among transmission terminals; and

FIG. 25 shows a concept of a destination list according to anotherembodiment of the present invention.

DESCRIPTION OF EMBODIMENTS

According to the embodiment of the present invention, a transmissionsystem selects a first relay apparatus in a case where a first attributedetermination part has determined that first attributes are the same,selects a second relay apparatus in a case where the first attributedetermination part has determined that the first attributes are not thesame but a second attribute determination part has determined thatsecond attributes are the same, and selects a third relay apparatus in acase where the first attribute determination part has determined thatthe first attributes are not the same and the second attributedetermination part has determined that the second attributes are not thesame. Thereby, it is possible to select an optimum relay apparatusdepending on the plural independent attributes.

Overall Configuration of Embodiment

Below, with reference to FIGS. 1A through 24, the embodiment of thepresent invention will be described. First, with reference to FIGS. 1Aand 1B, the embodiment of the present invention will be generallydescribed. FIGS. 1A and 1B generally show examples of respectivetransmission systems 1 a and 1 b according to the embodiment.

The transmission system 1 a or 1 b may be a data providing systemtransmitting content data in one direction from one transmissionterminal 10 to another transmission terminal 10 via a transmissionmanagement system, or a communication system transmitting information,feelings or such between plural transmission terminals 10 mutually via atransmission management system. The communication system is a system formutually transmitting information, feelings or such between pluralcommunication terminals (corresponding to “transmission terminals”) viaa communication management system 10 (corresponding to a “transmissionmanagement system”), and may be, as an example, a TV conference system,a teleconference system, a voice conference system, a voice telephonesystem, a PC (personal computer) screen sharing system, or such.

According to the embodiment, the transmission system, the transmissionmanagement system and the transmission terminals will be describedsupposing a TV conference system as one example of the communicationsystem, supposing a TV conference management system as one example ofthe communication management system and supposing a TV conferenceterminal as one example of the communication terminal. That is, thetransmission terminals and the transmission management system accordingto the embodiment of the present invention may be applied not only to aTV conference system, but also to a communication system or atransmission system. It is noted that the above-mentioned “TVconference” may also be called “video conference” or such.

The transmission system 1 a shown in FIG. 1A includes pluraltransmission terminals (10 aa, 10 ab, . . . ), display devices (120 aa,120 ab, . . . ) for the respective transmission terminals (10 aa, 10 ab,. . . ), plural relay apparatuses (30 a, 30 ab, 30 cd, 30 d and 30abcd), a transmission management system 50, a program providing system90 and a maintenance system 100.

It is noted that hereinafter, “transmission terminals” may be simplyreferred to as “terminals”, and “transmission management system” may besimply referred to as “management system”. Further, any terminal of theplural terminals (10 aa, 10 ab, . . . ) may be referred to as a“terminal 10”. Any display device of the plural display devices (120 aa,120 ab, . . . ) may be referred to as a “display device 120”. Any one ofthe plural relay apparatuses (30 a, 30 ab, 30 cd, 30 d and 30 abcd) maybe referred to as a “relay apparatus 30”.

The terminal 10 carries out transmission of image data and voice data asexamples of content data through transmission/reception of image dataand voice data. That is, a telephone call according to the embodimentincludes not only transmission and reception of voice data but alsotransmission and reception of image data. Thus, the terminal 10according to the embodiment transmits and receives image data and voicedata. However, the terminal 10 may transmit and receive voice datawithout transmitting and receiving image data.

It is noted that according to the embodiment, description will be madewhere images of the image data are video (moving picture) images.However, images of the image data may be static images instead of video(moving picture) images. Further, images of the image data may includeboth video (moving picture) images and static images. Further, the relayapparatus 30 relays image data and voice data among plural terminals 10.The management system 50 manages the terminals 10 and the relayapparatuses 30 in a unifying manner.

Further, plural routers (70 a, 70 b, 70 c, 70 d) select optimum pathsfor image data and voice data. It is noted that hereinafter, any one ofthe plural routers (70 a, 70 b, 70 c, 70 d) may be referred to as a“router 70”.

The program providing system 90 includes a HD (Hard Disk) (describedlater with reference to FIG. 4), stores a program for the terminals 10for each of the terminals 10 to carry out various functions (or causingeach of the terminals 10 to function as various functional parts), andis capable of transmitting the program for the terminals 10 to each ofthe terminals 10. Further, the HD of the program providing system 90also stores a program for the relay apparatuses 30 for each of the relayapparatuses 30 to carry out various functions (or causing each of therelay apparatuses 30 to function as various functional parts), andcapable of transmitting the program for the relay apparatuses 30 to eachof the relay apparatuses 30. Further, the HD of the program providingsystem 90 also stores a program for transmission management for themanagement system 50 to carry out various functions (or causing themanagement system 50 to function as various functional parts), andcapable of transmitting the program for transmission management to themanagement system 50.

The maintenance system 100 is a computer carrying out maintenance ormanagement of at least one of the terminals 10, the relay apparatuses30, the management system 50 and the program providing system 90. Forexample, in a case where the maintenance system 100 is installed in thehome country, and any one of the terminals 10, the relay apparatuses 30,the management system 50 and the program providing system 90 areinstalled abroad, the maintenance system 100 carries out maintenance,management or such of at least one of the terminals 10, the relayapparatuses 30, the management system 50 and the program providingsystem 90 remotely via the communication network 2. Further, themaintenance system 100 may carry out maintenance, management and soforth of a model number, a production number, a sales destination,maintenance inspection or a history of failures of at least one of theterminals 10, the relay apparatuses 30, the management system 50 and theprogram providing system 90 without using the communication network 2.

Further, the terminals (10 aa, 10 ab, . . . ), the relay apparatus 30 aand the router 70 a are connected together by a LAN 2 a in such a mannerthat they can carry out mutual communication, and are included in anintranet A. The terminals (10 ba, 10 bb, . . . ) and the router 70 b areconnected together by a LAN 2 b in such a manner that they can carry outmutual communication, and are included in an intranet B. For example,the intranet A is managed by an “A” company, and the LAN 2 a is providedwithin a Tokyo office. The intranet B is managed by a “B” company, andthe LAN 2 b is provided within an Osaka office. Further, the LAN 2 a andthe LAN 2 b are provided in a segment AB. “Segments” means divisions(areas or regions) divided in terms of the communication network 2 oraccording to geographic positions. The segment AB is, for example,Japan.

On the other hand, the terminals (10 ca, 10 cb, . . . ) and the router70 c are connected together by a LAN 2 c in such a manner that they cancarry out mutual communication, and are included in an intranet C. Theterminals (10 da, 10 db, . . . ), the relay apparatus 30 d and therouter 70 d are connected together by a LAN 2 d in such a manner thatthey can carry out mutual communication, and are included in an intranetD. For example, the intranet C is managed by a “C” company and the LAN 2c is provided within a New York office. The intranet D is managed by a“D” company and the LAN 2 d is provided within a Washington D.C. office.Further, the LAN 2 c and the LAN 2 d are provided in a segment CD. Thesegment CD is, for example, USA. The intranet A, intranet B, intranet Cand intranet D are connected in such a manner that they can carry outmutual communication by using the routers (70 a, 70 b, 70 c and 70 d),respectively, and using the Internet 2 i. It is noted that firewalls areprovided between the respective intranets (A, B, C and D) and theInternet 2 i.

Further, the terminal 10 has mobility, and may be connected with theInternet 2 i from an area different from an area where the terminal 10is usually installed, and may communicate content data with anotherterminal 10 via a relay apparatus 30. For example, the terminal 10 acmay be connected with the intranet A via the Internet 2 i from an areadifferent from an area (Tokyo) where the terminal 10 ac is usuallyinstalled, and may communicate content data with another terminal via arelay apparatus 30.

Further, as in the transmission system 1 b shown in FIG. 1B, the relayapparatuses (30 a, 30 d) may be connected to the LANs (2 a, 2 d)respectively through VPN (Virtual Private Network) connections (2 va, 2vb). Thereby, the relay apparatus 30 a may be installed in an area (forexample, a data center of a company which provides the transmissionsystem 1 b) different from an area (the Tokyo office of the A company)for which the LAN 2 a is provided. It is noted that the transmissionsystem 1 b of FIG. 1B has the same configuration as the transmissionsystem 1 a of FIG. 1A except that the relay apparatuses (30 a, 30 d) areconnected with the LANs (2 a, 2 d) respectively using the VPNconnections. It is noted that according to the embodiment, in a casewhere any one of the transmission systems 1 a and 1 b is referred to,“transmission system 1” is used.

In the transmission system 1 according to the embodiment, the relayapparatus 30 a is connected with the terminals (10 aa, 10 ab, . . . )and the management system 50 via the communication network 2 in such amanner that they can communicate with each other. The relay apparatus 30a is installed in the LAN 2 a or VPN 2 va for the purpose of making thecommunication paths more efficient. The relay apparatus 30 a is used torelay content data in a case where the terminals (10 aa, 10 ab, . . . )carry out telephone calls with other terminals 10 installed in the LAN 2a.

In the transmission system 1 according to the embodiment, the relayapparatus 30 d is connected with the terminals (10 da, 10 db, . . . )and the management system 50 via the communication network 2 in such amanner that they can communicate with each other. The relay apparatus 30d is installed in the LAN 2 d or VPN 2 vb for the purpose of making thecommunication paths more efficient. The relay apparatus 30 d is used torelay content data in a case where the terminals (10 da, 10 db, . . . )carry out telephone calls with other terminals 10 installed in the LAN 2d.

In the transmission system 1 according to the embodiment, the relayapparatus 30 ab is connected with the terminals (10 aa, 10 ab, . . . ,10 ba, 10 bb, . . . ) and the management system 50 via the communicationnetwork 2 in such a manner that they can communicate with each other.The relay apparatus 30 ab is installed in an area other than the area Aand area B for the purpose of not easily being influenced by thecommunication amount in the local area network of the area A or area B.The relay apparatus 30 ab is used to relay content data in a case wherethe terminals (10 aa, 10 ab, . . . , 10 ba, 10 bb, . . . ) carry outtelephone calls with other terminals 10 installed in the LANs (2 a, 2 b)(hereinafter, also referred to as a “segment AB”).

In the transmission system 1 according to the embodiment, the relayapparatus 30 cd is connected with the terminals (10 ca, 10 cb, . . . ,10 da, 10 db, . . . ) and the management system 50 via the communicationnetwork 2 in such a manner that they can communicate with each other.The relay apparatus 30 cd is installed in an area other than the area Cand area D for the purpose of not easily being influenced by thecommunication amount in the local area network of the area C or area D.The relay apparatus 30 ab is used to relay content data in a case wherethe terminals (10 ca, 10 cb, . . . , 10 da, 10 db, . . . ) carry outtelephone calls with other terminals installed in the LANs (2 c, 2 d)(hereinafter, also referred to as a “segment CD”).

In the transmission system 1 according to the embodiment, the relayapparatus 30 abcd is connected with the terminals (10 aa, 10 ab, . . . ,10 ba, 10 bb, . . . , 10 ca, 10 cb, . . . , 10 da, 10 db, . . . ) andthe management system 50 via the communication network 2 in such amanner that they can communicate with each other. The relay apparatus 30abcd is installed in an area other than the area A, area B, area C andarea D for the purpose of not easily being influenced by thecommunication amount in the local area network of the area A, area B,area C or area D. The relay apparatus 30 abcd is used to relay contentdata in a case where the terminals (10 aa, 10 ab, . . . , 10 ba, 10 bb,. . . , 10 ca, 10 cb, . . . , 10 da, 10 db, . . . ) carry out telephonecalls with other terminals installed in the LANs (2 a, 2 b, 2 c, 2 d).

Further, in the transmission system 1 according to the embodiment, themanagement system 50 and the program providing system 90 are connectedwith the terminals 10 and the relay apparatuses 30 in such a manner thatthey can carry out mutual communication by the Internet 2 i. Themanagement system 50 and the program providing system 90 may beinstalled in the area A, area B, area C or area D, or may be installedin another area.

It is noted that in the embodiment, the communication network 2 includesthe LAN 2 a, the LAN 2 b, the Internet 2 i, the LAN 2 c and the LAN 2 d.The communication network 2 may include not only parts where cablecommunication is carried out, but also parts where radio communicationis carried out.

Further, in FIG. 1A or 1B, four sets of numerals below each of theterminals 10, the relay apparatuses 30, the management system 50, therouters 70 and the program providing system 90 show an IP addressaccording to the common IPv4 in a simplified manner. For example, the IPaddress of the terminal 10 aa is “1.2.1.3”. IPv6 may be used instead ofIPv4. However, for the sake of simplifying the description, thedescription will be made supposing to use IPv4.

Hardware Configuration of Embodiment

Next, a hardware configuration of the embodiment will be described. FIG.2 shows one example of an external appearance of the terminal 10according to the embodiment. Below, a longitudinal direction of theterminal 10 is referred to as an X-axis direction, a directionperpendicular to the X-axis direction on the horizontal plane isreferred to as a Y-axis direction and a direction (vertical direction)perpendicular to the X-axis direction and the Y-axis direction isreferred to as a Z-axis direction.

As shown in FIG. 2, the terminal 10 includes a housing 1100, an arm 1200and a camera housing 1300. On a rear side wall 1110 of the housing 1100,an air suction surface (not shown) including plural air suction holes isprovided. On a front side wall 1120 of the housing 1100, an airdischarge surface 1121 including plural air discharge holes is provided.Thereby, as a result of a cooling fan (not shown) provided in the insideof the housing 1100 being driven, air behind the terminal 10 is taken invia the air suction surface, and the air is discharged to the front sideof the terminal 10 via the air discharge surface 1121. On a right sidewall 1130 of the housing 1100, a sound collecting hole 1131 is formed,and voice, sound, noise or such is collected by means of a microphone114 provided in the inside of the housing 1100 described later.

On a top surface of the housing 1100 at an area near the right side wall1130, an operations panel 1150 is provided. On the operations panel1150, plural operating buttons (108 a through 108 e) described later, apower supply switch 109 described later and an alarm lamp 119 describedlater are provided. Also, on the operations panel 1150, a sound outputsurface 1151 including plural sound output holes formed for passingthrough output sound from a speaker 115 provided in the inside of thehousing 1100 described later is provided. Further, on the top surface ofthe housing 1100 at an area near a left side wall 1140, a holding hole1160 as a depression for receiving the arm 1200 and the camera housing1300 is provided. On the right side wall 1130 of the housing 1100,plural connection holes (1132 a through 1132 c) are provided forelectrically connecting cables to an external apparatus connecting I/F118 described later. On the other hand, on the left side wall 1140 ofthe housing 1100, a connection hole (not shown) is provided forelectrically connecting a cable 120 c for the display device 120 to theexternal apparatus connecting I/F 118.

It is noted that hereinafter, in a case where any operating button ofthe operating buttons (108 a through 108 e) is referred to, this will begenerally referred to as an “operating button 108”. Similarly, in a casewhere any connection hole of the connection holes (1132 a through 1132e) is generally referred to, this will be referred to as a “connectionhole” 1132.

The arm 1200 is mounted on the housing 1100 via a torque hinge 1210, andis configured to be able to rotate vertically in a range of a tilt angleθ1 of 135° with respect to the housing 1100. FIG. 2 shows a state wherethe tilt angle θ1 is 90°.

A camera 112 in a built-in type described later is provided in thecamera housing 1300, and the user, a document, the room and so forth canbe photographed. Further, a torque hinge 1310 is formed in the camerahousing 1300. The camera housing 1300 is mounted on the arm 1200 via thetorque hinge 1310, and thus a configuration is provided such that thecamera housing 1300 can be rotated vertically and horizontally withrespect to the arm 1200, in a range of a pan angle θ2 of ±180° and in arange of a tilt angle θ3 of ±45°, where FIG. 2 shows a state of 0°.

It is noted that each of the relay apparatuses 30, the management system50, the program providing system 90 and the maintenance system 100 hasan external appearance the same as that of a common server computer.Therefore, description of the external appearances thereof will beomitted.

FIG. 3 shows a hardware configuration of the terminal 10 according tothe embodiment. As shown in FIG. 3, the terminal 10 according to theembodiment includes a CPU (Central Processing Unit) 101 controllingoperations of the entirety of the terminal 10; a ROM (Read Only Memory)102 storing a program for the terminals 10; a RAM (Random Access Memory)103 used as a work area of the CPU 101; and a flash memory 104 storingvarious data such as image data and voice data. The terminal 10according to the embodiment further includes a SSD (Solid State Drive)105 controlling reading and writing various data from and to the flashmemory 104 according to the control of the CPU 101; a media drive 107controlling reading and writing (recording) data from and to a recordingmedium 106 such as a flash memory; the operating buttons 108 operated bythe user in a case where the user selects a destination of the terminal10 or so; the power supply switch 109 for switching turning on/off ofthe power supply in the terminal 10; and a network I/F (InterFace) 111for transmitting data using the communication network 2 described later.

Further, the terminal 10 includes the camera 112 of a built-in typephotographing an object and obtaining image data according to thecontrol of the CPU 101; an image sensor I/F 113 controlling driving thecamera 112; the microphone 114 of a built-in type inputting voice; thespeaker 115 of a built-in type outputting voice; a voice input/outputI/F 116 processing input and output of voice signals from the microphone114 and to the speaker 115 according to the control of the CPU 101; anda display I/F 117 transmitting image data to the display device 120provided in the outside according to the control of the CPU 101. Theterminal 10 further includes the external apparatus connecting I/F 118for connecting various types of external apparatuses inserted in theconnection hole 1132 shown in FIG. 2; the alarm lamp 119 reportingunusual conditions of various functions of the terminal 10; and buslines 110 such as an address bus, a data bus and so forth forelectrically connecting the above-mentioned various elements/componentsas shown in FIG. 3.

The display device 120 is a display part made of a liquid crystal, anorganic electroluminescence (EL) material or such displaying an image ofan object, operating icons, or such. Further, the display device 120 isconnected with the display I/F 117 by the cable 120 c. The cable 120 cmay be a cable for an analog RGB (VGA) signal, a cable for a componentvideo signal, a cable for HDMI (High-Definition Multimedia Interface), acable for a DVI (Digital Video Interactive) signal, or such.

The camera 112 includes a lens and a solid state image sensor convertinglight into electric charge and obtaining a signal of an image (video) ofan object. As the solid state image sensor, a CMOS (Complementary MetalOxide Semiconductor) device, a CCD (Charge Coupled Device) or such maybe used.

To the external apparatus connecting I/F 118, external apparatuses (notshown) such as a camera provided in the outside, a microphone providedin the outside, a speaker provided in the outside or such may beelectrically connected by a USB (Universal Serial Bus) cable or such. Ina case where the camera provided in the outside is connected, thecameral provided in the outside is driven with a higher priority thanthe camera 112 of the built-in type according to the control of the CPU101. In a case where the microphone provided in the outside or thespeaker provided in the outside is connected, the microphone provided inthe outside or the speaker provided in the outside is driven with ahigher priority than the microphone 114 of the built-in type or thespeaker 115 of the built-in type according to the control of the CPU101.

It is noted that the recording medium 106 is freely detachable from theterminal 10. Further instead of the flash memory 104, an EEPROM(Electrically Erasable and Programmable ROM) or such may be used as longas it is a non-volatile memory for reading and writing data accordingthe control of the CPU 101.

The above-mentioned program for the terminals 10 may be recorded in acomputer readable information recording medium (the recording medium 106or such) in a form of a file of an installable type or an executabletype, and be circulated. Further, the program for the terminals 10 maybe stored in the ROM 102 instead of the flash memory 104.

FIG. 4 shows a hardware configuration of the management system 50according to the embodiment. The management system 50 includes a CPU 201controlling operations of the entirety of the management system 50; aROM 202 storing a program for transmission management; a RAM 203 used asa work area of the CPU 201; a HD (hard disk) 204 storing various data; aHDD (Hard Disk Drive) 205 controlling reading and writing of the variousdata from and to the HD 204 according to the control of the CPU 201; amedia drive 207 controlling reading and writing (recording) of data fromand to a recording medium 206 such as a flash memory; and a displaydevice 208 displaying various sorts of information such as a cursor, amenu, a window (screen page), characters/letters (text) or an image. Themanagement system 50 further includes a network I/F 209 for carrying outdata transmission using the communication network 2 described later; akeyboard 211 including plural keys for the user to inputcharacters/letters, numerical values, various instructions and so forth;a mouse 212 for the user to select or execute various instructions,select a target to process, move the cursor or so; a CD-ROM drive 214controlling reading various data from a CD-ROM (Compact Disc Read OnlyMemory) 213 as an example of a detachable recording medium; and buslines 210 such as an address bus, a data bus and so forth electricallyconnecting the above-mentioned respective elements/components togetheras shown in FIG. 4. The reference numeral “215” denotes “ports” (P1, P2,P3, . . . ) which will be described later in the description of therelay apparatuses 30.

It is noted that the program for transmission management may be recordedin a computer readable information recording medium such as theabove-mentioned recording medium 206, CD-ROM 213 or such in a form of afile of an installable type or an executable type, and be circulated.

Further, the relay apparatus 30 has the same hardware configuration asthat of the management system 50, and therefore, the description thereofwill be omitted. However, in the ROM 202 of the relay apparatus 30, aprogram for the relay apparatuses 30 for controlling the relayapparatuses 30 is recorded. Also in this case, the program for the relayapparatuses 30 may be recorded in a computer readable informationrecording medium such as the recording medium 206, the CD-ROM 213 orsuch in a form of a file of an installable type or an executable type,and be circulated. Further, as mentioned above, at least the relayapparatus 30 has the ports 215 (P1, P2, P3, . . . ) (configured ashardware or software) used in communication with terminals 10 and theports 215 may be actually included in the network I/F 209.

Further, the program providing system 90 has the same hardwareconfiguration as that of the management system 50, and therefore, thedescription thereof will be omitted. However, in the ROM 202 of theprogram providing system 90, a program for providing programs forcontrolling the program providing system 90 is recorded. Also in thiscase, the program for providing programs may be recorded in a computerreadable information recording medium such as the recording medium 206,the CD-ROM 213 or such in a form of a file of an installable type or anexecutable type, and be circulated.

Further, the maintenance system 100 has the same hardware configurationas that of the management system 50, and therefore, the descriptionthereof will be omitted. However, in the ROM 202 of the maintenancesystem 100, a program for maintenance for controlling the maintenancesystem 100 is recorded. Also in this case, the program for maintenancemay be recorded in a computer readable information recording medium suchas the recording medium 206, the CD-ROM 213 or such in a form of a fileof an installable type or an executable type, and be circulated.

It is noted that each of the above-mentioned programs may be recorded ina computer readable information recording medium such as a CD-R (CompactDisc Recordable), a DVD (Digital Versatile Disk) or a Blu-ray Disc, asother examples of the above-mentioned detachable recording medium, andbe provided.

Functional Configuration of Embodiment

Next, a functional configuration of the embodiment will be described.FIG. 5 shows a functional block diagram of the terminal 10, the relayapparatus 30 and the management system 50 included in the transmissionsystem 1 according to the embodiment. In FIG. 5, the terminal 10, therelay apparatus 30 and the management system 50 are connected togetherby the communication network 2 in such a manner that data transmissioncan be mutually carried out. Further, the program providing system 90and the maintenance system 100 shown in FIGS. 1A and 1B are omitted inFIG. 5 because the program providing system 90 and the maintenancesystem 100 do not directly relate to communication for a TV conference.

<Functional Configuration of Terminal>

The terminal 10 includes a communication part 11, an operation inputreception part 12, a login request part 13, a photographing part 14, avoice input part 15 a, a voice output part 15 b, a display control part16, a delay detection part 18, a storing/reading processing part 19 anda destination list creation part 20. The parts correspond to functionsor functioning parts realized as a result of the respectiveelements/components shown in FIG. 3 operating according to instructionsgiven by the CPU 101 that operates according to the program stored inthe ROM 102. Further, the terminal 10 has a non-volatile storage part1000 provided by the flash memory 104 shown in FIG. 3 and a volatilestorage part 1002 provided by the RAM 103 shown in FIG. 3.

(Detailed Functional Configuration of Terminal)

Next, the respective parts of the terminal 10 will be described indetail. The communication part 11 of the terminal 10 is realized by thenetwork I/F 111 shown in FIG. 3, and carries out transmission andreception of various sorts of data (or information) with anotherterminal 10, apparatus 30 or system via the communication network 2. Thecommunication part 11 starts reception of respective state informationindicating states of respective terminals 10 as candidates for adestination from the management system 50 before starting a telephonecall with a terminal 10 (destination terminal) as a desired destination.It is noted that the state information indicates not only an operatingstate (on-line or off-line) of each terminal 10 but also a detailedstate of whether on telephone call (i.e., during a telephone call)further when on-line, or so. Further, the state information indicatesvarious states including not only the operating state of each terminal10 but also whether the cable (120 c) has been removed from the terminal10, whether the terminal 10 has been set to output voice but not outputan image, or set to output no voice (MUTE), or so. Below, a case issupposed that, as one example, the state information indicates anoperating state of the terminal 10.

The operation input reception part 12 is realized by the operatingbuttons 108 and the power supply switch 109, and receives various sortsof input operations carried out by the user. For example, when the userturns on the power supply switch 109, the operation input reception part12 shown in FIG. 5 turns on the power supply in the terminal 10 byreceiving the user's operation of turning on the power supply switch109. The login request part 13 is realized by instructions from the CPU101 shown in FIG. 3, and automatically transmits login requestinformation indicating to request login and an IP address (at thecurrent time) of the terminal 10 (request source terminal) as a requestsource to the management system 50 via the communication network 2 fromthe communication part 11 in response to receiving the user's operationof turning on the power supply switch 109. Further, when the user turnsoff the power supply switch 109, the communication part 11 transmitsstate information to turn off the power supply to the management system50, and after that, the operation input reception part 12 completelyturns off the power supply in the terminal 10. Thus, the managementsystem 50 can determine that the terminal 10 is changing its state fromthe power turned on (power supply ON) to the power turned off (powersupply OFF).

The photographing part 14 is realized by instructions from the CPU 101,and the camera 112 and the image sensor I/F 113 shown in FIG. 3, andphotographs an object and outputs image data thus obtained from thephotographing. The voice input part 15 a is realized by the voiceinput/output I/F 116 shown in FIG. 3, and inputs voice data expressed bya voice signal when a voice of the user is converted into the voicesignal by the microphone 114. The voice output part 15 b is realized byinstructions from the CPU 101 and the voice input/output I/F 116, andoutputs a voice signal expressing voice data to the speaker 115 andcauses the speaker 115 to output voice sound.

The display control part 16 is realized by the display I/F 117 shown inFIG. 3, and carries out control to transmit image data to the displaydevice 120 provided in the outside. Further, the display control part 16displays a destination list, including respective destination namesbased on the state information received by the communication part 11, onthe display device 120, before a request source terminal starts atelephone call of a TV conference with a desired destination terminal.

For example, on the display device 120, by the display control part 16,a destination list frame 311-1 such as that shown in FIG. 21 isdisplayed. In the destination list frame 311-1, respective destinationnames such as “A company Tokyo office AB terminal” 311-2 and so forthare displayed, and icons (311-3 a, 311-3 b, 311-3 c) indicating statesof the state information for the respective destination names aredisplayed. Thereamong, the icon 311-3 a indicates that since oneterminal 10 as a destination candidate is waiting in an on-line state,it is possible to carry out a telephone call with the terminal. The icon311-3 b indicates that since one terminal 10 as a destination candidateis in an off-line state, it is not possible to carry out a telephonecall with the terminal. The icon 311-3 c indicates that since oneterminal 10 as a destination candidate is carrying out a telephone callwith another terminal (i.e., “on telephone call”), it is possible toparticipate in the telephone call. Further, in the destination listframe 311-1, a scroll bar 311-4 is displayed at a right end, where whena triangular upward or downward icon is selected by the user,destination names as destination candidates and icons indicating thecorresponding states, not displayed in FIG. 21, will be then displayed.

The delay detection part 18 is realized by instructions given by the CPU101, and detects a delay time (ms) of image data or voice data sent fromanother terminal 10 via a relay apparatus 30.

Further, the storing/reading processing part 19 is realized byinstructions from the CPU 101 and, for example, by the SSD 105 shown inFIG. 3, stores various sorts of data in the non-volatile storage part1000, and reads various sorts of data stored in the non-volatile storagepart 1000. In the non-volatile storage part 1000, terminal IDs(identifications) for identifying the terminals 10, respectively,passwords and so forth, are stored. Further, the storing/readingprocessing part 19 also stores various sorts of data in the volatilestorage part 1002, and reads various sorts of data stored in thevolatile storage part 1002. In the volatile storage part 1002, imagedata and voice data received when a telephone call is carried out with adestination terminal 10 are stored in an overwriting manner each time ofreceiving. There, an image is displayed on the display device 120 fromthe image data before being overwritten, and voice audio is output fromthe speaker 115 from the voice data before being overwritten.

The destination list creation part 20 creates and updates thedestination list where, as shown in FIG. 21, the states of destinationcandidates are indicated by the icons, as mentioned above, based ondestination list information (described later) and state information ofterminals 10 as destination candidates received from the managementsystem 50.

It is noted that the terminal IDs and relay apparatus IDs describedlater according to the embodiment indicate identification informationsuch as a language, a character/letter, a sign or various sorts of marksused for uniquely identifying the respective terminals 10 and relayapparatuses 30. Further, each of the terminal IDs and the relayapparatus IDs may be identification information that is a combination ofat least two of the above-mentioned language, character/letter, sign andvarious sorts of marks.

<Functional Configuration of Relay Apparatus>

Next, functions or parts of the relay apparatus 30 will be described.The relay apparatus 30 includes, as shown in FIG. 5, a communicationpart 31, a state detection part 32, a data quality determination part33, a change quality management part 34, a data quality changing part 35and a storing/reading processing part 39. These parts correspond tofunctions or functioning parts realized as a result of the respectiveelements/components shown in FIG. 4 operating according to instructionsgiven by the CPU 201 that operates according to the program stored inthe ROM 202. Further, the relay apparatus 30 has a non-volatile storagepart 3000 provided in the HD 204 shown in FIG. 4, where even when thepower supply in the relay apparatus 30 is turned off, various sorts ofdata and/or information stored therein are maintained.

(Change Quality Management Table)

In the non-volatile storage part 3000, a change quality management DB(DataBase) 3001 including a change quality management table such as thatshown in FIG. 7 is provided. FIG. 7 shows a concept of the changequality management table. In the change quality management table, the IPaddress of a terminal 10 as a relay destination of image data and imagequality of the image of the image data relayed by the relay apparatus 30to the relay destination are associated with one another and aremanaged.

Resolution of image data used in the embodiment will now be describedwith reference to FIGS. 8A, 8B and 8C which are conceptual diagramsillustrating image quality (quality of the image) of image data. Asshown in FIG. 8A, an image of low resolution as a base image has aconfiguration of 160 pixels (in a horizontal direction) by 120 pixels(in a vertical direction). As shown in FIG. 8B, an image of mediumresolution has a configuration of 320 pixels (in the horizontaldirection) by 240 pixels (in the vertical direction). As shown in FIG.8C, an image of high resolution has a configuration of 640 pixels (inthe horizontal direction) by 480 pixels (in the vertical direction). Ina case where a narrow band path is used, image data of low image qualityincluding only image data of low resolution as a base image is relayed.In a case where a band is relatively wide, image data of medium imagequality including image data of low resolution as a base image and imagedata of medium resolution are relayed. In a case where a band is verywide, image data of high image quality including image data of lowresolution as a base image, image data of medium resolution and imagedata of high resolution are relayed. For example, in the change qualitymanagement table shown in FIG. 7, in a case where a relay apparatus 30relays image data to a destination terminal (terminal 10 db) of the IPaddress “1.3.2.4”, the image quality (quality of the image) of imagedata being relayed is “high quality” (“high image quality”).

(Detailed Functional Configuration of Relay Apparatus)

Next, the functional configuration of each of the parts of the relayapparatus 30 will be described in detail. It is noted that below, alongwith describing the functional configuration of each of the parts of therelay apparatus 30, relationships with main elements/components, fromamong those shown in FIG. 4, used for realizing the functionalconfiguration of each of the parts of the relay apparatus 30 will bealso described.

The communication part 31 of the relay apparatus 30 shown in FIG. 5 isrealized by the network I/F 209 shown in FIG. 4, and carries outtransmission and reception of various sorts of data (information) with aterminal 10, another apparatus or a system via the communication network2. The state detection part 32 is realized by instructions from the CPU201 shown in FIG. 4, and detects the operating state of the relayapparatus 30 (own apparatus) having this state detection part 32. Theoperating state may be a state of “on-line”, “off-line” or “in failure”.

The data quality determination part 33 is realized by instructions fromthe CPU 201 shown in FIG. 4, searches the change quality managementtable (see FIG. 7) of the change quality management DB 3001 using the IPaddress of a destination terminal as a search key, extracts the imagequality of the corresponding image data to be relayed, and thusdetermines the current image quality of the image data to be relayed.The change quality management part 34 is realized by instructions fromthe CPU 201, and changes the contents of the change quality managementtable based on quality information (described later) which is sent fromthe management system 50. For example, a case is supposed where a TVconference is being conducted between a request source terminal(terminal 10 aa) having the terminal ID “01aa” and a destinationterminal (terminal 10 db) having the terminal ID “01db” where image dataof high image quality is mutually transmitted, and a delay in receivingthe image data occurs in the destination terminal (terminal 10 db)because another request source terminal (terminal 10 bb) and anotherdestination terminal (10 ca) have started another TV conference usingthe communication network 2, or so. In such a case, the relay apparatus30 needs to reduce the image quality of the image data, having beenrelayed by the relay apparatus 30 until now, from the high image qualityto the medium image quality. In such a case, based on the qualityinformation indicating this medium image quality, the contents of thechange quality management table are changed so that the image quality ofthe image data which the relay apparatus 30 is relaying is reduced fromthe high image quality to the medium image quality.

The data quality changing part 35 is realized by instructions from theCPU 201, and changes the image quality of the image data sent from thetransmission source terminal 10 based on the contents of the changequality management table of the change quality management DB 3001changed as mentioned above. The storing/reading processing part 39 isrealized by the HDD 205 shown in FIG. 4, and carries out processing ofrecording various sorts of data in the non-volatile storage part 3000and reading various sorts of data stored in the non-volatile storagepart 3000.

<Functional Configuration of Management system>

Next, functions or parts of the management system 50 will be described.The management system 50 includes, as shown in FIG. 5, a communicationpart 51, a terminal authentication part 52, a state management part 53,a terminal extraction part 54, a terminal state obtaining part 55, arelay apparatus selection part 56, a session management part 57, aquality management part 58, a storing/reading processing part 59 and adelay time management part 60. These respective parts correspond tofunctions or functioning parts realized as a result of the respectiveelements/components shown in FIG. 4 operating according to instructionsgiven by the CPU 201 that operates according to the program stored inthe ROM 202. Further, the management system 50 has a non-volatilestorage part 5000 realized by the HD 204 shown in FIG. 4 where varioussorts of data (or information) are maintained even after the powersupply in the management system 50 is turned off. In the non-volatilestorage part 5000, data of the destination list frame 311-1 shown inFIG. 21 is stored.

(Relay Apparatus Management Table)

In the non-volatile storage part 5000, further, a relay apparatusmanagement DB 5001 including a relay apparatus management table such asthat shown in FIG. 9 is provided. It is noted that FIG. 9 shows aconcept of the relay apparatus management table. In the relay apparatusmanagement table, for each of respective relay apparatus IDs of therespective relay apparatuses 30, the operating state of each of therelay apparatuses 30, the number of ports used and the number of ports(215, P1, P2, P3, . . . , see FIG. 4) usable in each of the relayapparatuses 30, reception date and time when the state informationindicating the operating state of each of the relay apparatuses 30 hasbeen received by the management system 50, the IP address of each of therelay apparatuses 30, and the maximum data transmission rate (Mbps) ateach of the relay apparatus 30, are associated and managed. For example,in the relay apparatus management table shown in FIG. 9, for the relayapparatus 30 a having the relay apparatus ID “111a”, it is indicatedthat the operating state is “on-line”; the number of ports used is “10”;the number of ports usable is “100”; the date and time when the stateinformation has been received in the management system 50 are “Nov. 10,2009, 13:00”; the IP address of the relay apparatus 30 a is “1.2.1.2”;and the maximum transmission rate at the relay apparatus 30 a is 100Mbps.

(Terminal Authentication Management Table)

Further, in the non-volatile storage part 5000, a terminalauthentication management DB 5001 including a terminal authenticationmanagement table such as that shown in FIG. 10 is provided. FIG. 10shows a concept of the terminal authentication management table. In theterminal authentication management table, respective passwords areassociated with the terminal IDs of all the terminals 10 managed by themanagement system 50 and are managed. For example, in the terminalauthentication management table shown in FIG. 10, it is indicated thatthe terminal ID of the terminal 10 aa is “01aa”, and the passwordthereof is “aaaa”.

(Terminal Management Table)

Further, in the non-volatile storage part 5000, a terminal management DB5003 including a terminal management table such as that shown in FIG. 11is stored. FIG. 11 shows a concept of the terminal management table. Inthe terminal management table, for the terminal ID of each of theterminals 10, a destination name (i.e., terminal name) for a case wherethe terminal 10 acts as a destination, the operating state of theterminal 10, the reception date and time when login request information(described later) has been received by the management system 50, and theIP address of the terminal 10 are associated and are managed. Forexample, in the terminal management table shown in FIG. 11, it isindicated that the terminal 10 aa having the terminal ID “01aa” has thedestination name “Japan Tokyo office AA terminal”, the operating state“on-line”, the reception date and time when the login requestinformation has been received in the management system 50 is “Nov. 10,2009, 13:40”, and the IP address of the terminal 10 aa is “1.2.1.3”.

(Destination List Management Table)

Further, in the non-volatile storage part 5000, a destination listmanagement DB 5004 including a destination list management table such asthat shown in FIG. 12 is stored. FIG. 12 shows a concept of thedestination list management table. In the destination list managementtable, for the terminal ID of a request source terminal which requeststo start a telephone call in a TV conference, all of the terminal IDs ofthe destination terminals registered as candidates for a destinationterminal are associated and are managed. For example, in the destinationlist management table shown in FIG. 12, it is indicated that thecandidates for a destination terminal for which the request sourceterminal (terminal 10 aa) having the terminal ID “01aa” can request tostart a telephone call in a TV conference are the terminal 10 ab havingthe terminal ID “01ab, the terminal 10 ba having the terminal ID “01ba”,the terminal 10 bb having the terminal ID “01bb” and so forth. Thecandidates for a destination terminal are updated as a result ofaddition or deletion according to a request of addition or deletion fromthe request source terminal to the management system 50.

(Session Management Table)

Further, in the non-volatile storage part 5000, a session management DB5005 including a session management table such as that shown in FIG. 13is provided. FIG. 13 shows a concept of the session management table. Inthe session management table, for each of session IDs used foridentifying sessions in which content data is communicated betweenterminals 10, the relay apparatus ID of the relay apparatus 30 used forrelaying image data and voice data, the terminal ID of the requestsource terminal, the terminal ID of the destination terminal, a delaytime (ms) of reception when image data is received in the destinationterminal, and the reception date and time when delay informationindicating the delay time has been sent from the destination terminaland received in the management system 50 are associated and managed. Forexample, in the session management table shown in FIG. 13, it isindicated that the relay apparatus 30 a (the relay apparatus ID “111a”)selected in the session executed using the selection session ID “se1” isrelaying image data and voice data between the request source terminal(terminal 10 aa) of the terminal ID “01aa”, and the destination terminal(terminal 10 bb) of the terminal ID “01bb”, the destination terminal(terminal 10 cb) of the terminal ID “01cb” and the destination terminal(terminal 10 db) of the terminal ID “01db”, and the delay time of theimage data is 200 (ms) at the time of “Nov. 10, 2009, 14:00”. It isnoted that in a case where a TV conference is carried out between twoterminals 10, the reception date and time of the delay information maybe managed based on the delay information sent from the request sourceterminal instead of the destination terminal. However, in a case where aTV conference is conducted between three or more terminals 10, thereception date and time of the delay information is managed based on thedelay information sent from the terminal which is receiving the imagedata and the voice data.

(Quality Management Table)

Further, in the non-volatile storage part 5000, a quality management DB5007 including a quality management table such as that shown in FIG. 14is stored. FIG. 14 shows a concept of the quality management table. Inthe quality management table, the delay time of image data and imagequality (quality of the image) of the image data are associated with oneanother and are managed in such a manner that as the delay time (ms) ofimage data at a request source terminal or a destination terminal islonger, the image quality of the image data relayed by the relayapparatus 30 is to be reduced. It is noted that in a case where thedelay time is more than “500 ms”, the communication is to be interrupted(“INTERRUPTION”) since the delay is too much.

(Attribute Management Table)

Further, in the non-volatile storage part 5000, an attribute managementDB 5008 including an attribute management table such as that shown inFIG. 15 is stored. FIG. 15 shows a concept of the attribute managementtable. In the attribute management table, first attribute informationindicating a first attribute of the terminal 10 and second attributeinformation indicating a second attribute of the terminal 10 areassociate with each of the terminal IDs of all the terminals managed bythe management system 50, and are managed. Here, the first attributeinformation indicates the first attribute which is an attributeconcerning a certain communication network (intranet, i.e., a part ofthe communication network 2) with which the terminal 10 is connected.More specifically, the first attribute is the relay apparatus ID(hereinafter, referred to as “intranet relay apparatus ID”) foridentifying the relay apparatus 30 connected to the certaincommunication network. The second attribute information indicates thesecond attribute which indicates an attribute concerning a certain areawhere the terminal 10 is connected to the communication network 2. Morespecifically, the second attribute is the relay apparatus ID(hereinafter, referred to as “segment relay apparatus ID”) foridentifying the relay apparatus 30 connected to the communicationnetwork 2 from the certain area. That is, in the attribute managementtable shown in FIG. 15, for each of the terminals 10, the relayapparatus ID of the relay apparatus 30 which is to be assignedpreferentially for relaying image data and voice data is associated andmanaged.

(Detailed Functional Configuration of Management System)

Next, the functional configuration of each of the parts included in themanagement system 50 will be described in detail. It is noted that belowalong with describing the respective functional configurations of theparts of the management system 50, relationships with mainelements/components, from among those shown in FIG. 4, used forrealizing the respective functional configurations of the parts of themanagement system 50 will be also described.

The communication part 51 is realized by the network I/F 209 shown inFIG. 4, and carries out transmission and reception of various sorts ofdata (information) with a terminal 10, a relay apparatus 30 or anothersystem via the communication network 2. The terminal authentication part52 searches the terminal authentication management table (see FIG. 10)in the non-volatile storage part 5000 using the terminal ID and thepassword included in login request information received via thecommunication part 51 as search keys, and carries out authentication ofthe terminal 10 by determining whether the same terminal ID and passwordare managed in the terminal authentication management table.

For the purpose of managing the operating state of a request sourceterminal which has requested to login, the state management part 53stores the terminal ID of the request source terminal, the operatingstate of the request source terminal, the reception date and time whenthe login request information has been received in the management system50 and the IP address of the request source terminal in the terminalmanagement table (see FIG. 11) in a manner of associating them with eachother and manages them. Further, the terminal management part 53 changesthe corresponding operating state indicating on-line in the terminalmanagement table (see FIG. 11) into off-line based on state informationindicating that power supply will be turned off sent from a terminal 10in response to the user of the terminal 10 turning off the power supplyswitch 109 of the terminal 10.

The terminal extraction part 54 searches the destination list managementtable of the destination list management DB 5004 (see FIG. 12) using theterminal ID of a request source terminal which has requested to login asa search key, reads the terminal IDs as candidates for a destinationterminal which can carry out a telephone call with the request sourceterminal, and extracts the terminal IDs. Further, the terminalextraction part 54 searches the destination list management DB 5004 (seeFIG. 12) using the terminal ID of a request source terminal which hasrequested to login as a search key, and extracts also the terminal IDsof the other request source terminals which have registered the terminalID of the request source terminal as a candidate for a destinationterminal.

The terminal state obtaining part 55 searches the terminal managementtable of the terminal management DB 5003 (see FIG. 11) using theterminal IDs of candidates for a destination terminal extracted by theterminal extraction part 54 as search keys, and reads the operatingstate for each of the terminal IDs extracted by the terminal extractionpart 54. Thereby, the terminal state obtaining part 55 can obtain theoperating states of the candidates for a destination terminal which cancarry out a telephone call with the request source terminal havingrequested to login. Further, the terminal state obtaining part 55searches the terminal management table using the terminal ID of therequest source terminal having requested to login, and obtains theoperating state of the request source terminal having requested tologin.

The relay apparatus selection part 56 selects a relay apparatus 30 usedfor relaying image data and voice data for each of sessions in whichcontent data is communicated between terminals 10. For this purpose, therelay apparatus selection part 56 realizes, according to instructionsgiven by the CPU 201 shown in FIG. 4, a session ID generation part 56 a,a destination determination part 56 b, an attribute extraction part 56c, an attribute determination part 56 d and a selection part 56 e shownin FIG. 6. It is noted that FIG. 6 is a functional block diagram showingdetails of the relay apparatus selection part 56 shown in FIG. 5.

Thereamong, the session ID generation part 56 a generates a session IDfor identifying a session in which content data is communicated betweenterminals 10. The destination determination part 56 b determines whetherthe terminal ID of a request source terminal of a TV conference is thesame as the terminal ID of a destination terminal which is a requesttarget. The attribute extraction part 56 c searches the attributemanagement table of the attribute management DB 5008 (see FIG. 15) basedon the terminal IDs of the request source terminal and the destinationterminal, and extracts the corresponding attributes. The attributedetermination part 56 d determines whether the attributes of therespective terminals 10 extracted by the attribute extraction part 56 care the same. The selection part 56 e selects a relay apparatus 30 basedon the attributes extracted by the attribute extraction part 56 c.

The session management part 57 stores the session ID generated by thesession ID generation part 56 a, the terminal ID of the request sourceterminal and the terminal ID of the destination terminal in a manner ofassociating them with each other in the session management table of thesession management DB 5005 (see FIG. 13) of the non-volatile storagepart 5000, and manages them. Further, the session management part 57stores for each of the session IDs, the relay apparatus ID of the relayapparatus 30 selected by the selection part 56 e in the sessionmanagement DB 5005 (see FIG. 13) and manages them.

The quality determination part 58 searches the quality management tableof the quality management DB 5007 (see FIG. 14) using theabove-mentioned delay time as a search key, extracts the image qualityof the corresponding image data, and determines the image quality of theimage data to be relayed by the relay apparatus 30. The storing/readingprocessing part 59 is realized by the HDD 205 shown in FIG. 4, storesvarious sorts of data in the non-volatile storage part 5000 and readsvarious sorts of data stored in the non-volatile storage part 5000. Thedelay time management part 60 searches the terminal management table(see FIG. 11) using the IP address of the above-mentioned destinationterminal, extracts the corresponding terminal ID, and further stores thedelay time indicated by the above-mentioned delay information at thefield of delay time on the record including the thus-extracted terminalID in the session management table of the session management DB 5005(see FIG. 13), and manages it.

Processing/Operations of Embodiment

Thus, the configuration and functions (or parts) of the transmissionsystem 1 according to the embodiment have been described. Next, usingFIGS. 16 through 23, a processing method in the transmission system 1according to the embodiment will be described. FIG. 16 is a sequencediagram showing a process of managing the state information indicatingthe respective operating states of the relay apparatuses 30 transmittedfrom the relay apparatus to the management system 50. FIG. 17 is ageneral view showing a state where image data, voice data and varioussorts of management information are transmitted in the transmissionsystem 1. FIG. 18 is a sequence diagram showing a process in apreparation step for starting a telephone call between plural terminals10. FIG. 19 is a sequence diagram showing a process of selecting a relayapparatus 30. FIG. 20 is a flowchart showing a process of selecting arelay apparatus 30. FIG. 21 shows a concept of the destination listaccording to the embodiment. FIG. 22 is a sequence diagram showing aprocess of requesting participation in a image and voice data session.FIG. 23 is a flowchart showing a process of selecting a relay apparatus30. FIG. 24 is a sequence diagram showing a process of transmittingimage data and voice data among terminals 10. FIG. 25 shows a concept ofthe destination list according to another embodiment of the presentinvention.

First, using FIG. 16, a process of managing the state informationindicating the state of each relay apparatus 30 transmitted to themanagement system 50 from the own relay apparatus 30 will be described.First, at each of the relay apparatuses 30, the state detection part 32shown in FIG. 5 periodically detects the operating state of the ownapparatus (relay apparatus 30) (steps S1-1 through S1-4). Further, thestate detection part 32 detects the number of ports (215, P1, P2, P3, .. . , see FIG. 4, i.e., “the number of ports usable”) of the relayapparatus 30 as the own apparatus, which ports can be used forcommunication with terminals 10; and the number of ports (“the number ofports used”) among the usable ports being actually used forcommunication with terminals 10. Then, in order to cause the managementsystem 50 to manage the operating states of the respective relayapparatuses 30 in a real-time manner, the communication part 31 of eachrelay apparatus 30 periodically transmits the own state information tothe management system 50 (steps S2-1 through S2-4). Each set of thestate information includes the relay apparatus ID of the correspondingrelay apparatus 30 and the operating state detected by the statedetection part 32 of the relay apparatus having the relay apparatus ID.Further, each set of the state information includes port informationincluding the above-mentioned number of ports usable and the number ofports used.

In the above-mentioned steps (steps S2-1 through S2-4) of transmittingthe state information, in a case where the relay apparatus 30 transmitsthe state information via a firewall, it is preferable to carry outsecure communication for the purpose of ensuring security. Securecommunication means that communication is carried out using a means bywhich the communication contents are not understandable to theunauthorized persons. Specifically, for example, communication using TLS(Transport Layer Security, which may also be referred to as SSL (SecureSockets Layer)), a tunneling service or such, may be used. For example,in the transmission system 1 shown in FIG. 1A, the communication parts31 included in the relay apparatuses (30 a, 30 d) included in theintranets may transmit the state information by using SSL to themanagement system 50. Further, in a case where it is not possible tocarry out communication using SSL, the communication parts 31 includedin the relay apparatuses (30 a, 30 d) may map the communication tosecure ports. This mapping may be realized by using a known tunnelingservice, for example, Stunnel (multiplatform SSL tunneling proxy) orsuch. Specifically, the communication parts 31 may map SSL ports toports of mail servers, and thereby, it is possible to establish secureconnections with the management system 50.

Next, the communication part 51 of the management system 50 receives thesets of state information thus sent from the respective relayapparatuses 30. In a case where the communication has been mapped asmentioned above, it is possible to receive the state information byusing the tunneling service of the management system 50. The managementsystem 50 stores the state information for each of the relay apparatusIDs in the relay apparatus management table (see FIG. 9) in thenon-volatile storage part 5000 via the storing/reading processing part59 (steps S3-1 through S3-4). Thereby, as shown in FIG. 9, in the relayapparatus management table, for each of the relay apparatus IDs, any oneof operating states of “on-line”, “off-line” and “in failure” is storedand managed. Further, for each of the relay apparatus IDs, the portinformation including the number of ports usable and the number of portsused is stored and managed. Further, at this time, for each of the relayapparatus IDs, the reception date and time when the state informationhas been received in the management system 50 is stored and managed. Itis noted that in a case where the state information has not been sentfrom the relay apparatus 30, the field area of operating state and thefield area of reception date and time on the corresponding record in therelay apparatus management table shown in FIG. 9 become blank, or showthe operating state and the reception date and time at the time of thepreceding reception.

Next, using FIG. 17, a concept of a state where image data, voice dataand various sorts of management information are transmitted and receivedin the transmission system 1 will be described. As shown in FIG. 17, inthe transmission system 1, among a terminal 10 a, a terminal 10 b and aterminal 10C, a management information session “sei” is established fortransmitting various sorts of management information via the managementsystem 50. Further, among the terminal 10 a, terminal 10 b and terminal10C, four sessions are established for transmitting four sorts of data,i.e., image data of high resolution, image data of medium resolution,image data of low resolution and voice data, respectively, via the relayapparatus 30. These four sessions may be collectively referred to as theimage and voice data session “sed”.

Next, with reference to FIG. 18, a process of transmission/reception ofvarious sorts of management information at a preparation stage beforestarting a telephone call between the terminal 10 aa and the terminal 10db will be described. It is noted that in FIG. 18, various sorts ofmanagement information are transmitted and received by the managementinformation session “sei”.

First, when the user of the terminal 10 aa turns on the power supplyswitch 109 shown in FIG. 3, the operation input reception part 12 shownin FIG. 5 receives the power supply turning on operation, and turns onthe power supply in the terminal 10 aa (step S21). Next, in response toreception of the above-mentioned power supply turning on operation, thelogin request part 13 automatically transmits login request informationindicating a login request to the management system 50 via thecommunication network 2 from the communication part 11 (step S22). Thelogin request information includes the terminal ID for identifying theown terminal (terminal 10 aa) as the request source and the password.The terminal ID and password are data having been read out from thenon-volatile storage part 1000 via the storing/reading processing part19 and having been sent to the communication part 11. It is noted thatwhen the login request information is transmitted to the managementsystem 50 from the terminal 10 aa, the management system 50 that hasreceived the login request information can obtain the IP address of theterminal 10 aa that has sent the login request information.

Next, the terminal authentication part 52 in the management system 50searches the terminal authentication management DB 5002 (see FIG. 10) ofthe non-volatile storage part 5000 using the terminal ID and thepassword included in the login request information having been receivedvia the communication part 51 as search keys, determines whether thesame terminal ID and password are managed in the terminal authenticationmanagement DB 5002, and thus, carries out authentication of the terminal(step S23).

In a case where it has been determined by the terminal authenticationpart 52 that the login request is one sent from the terminal 10 havingproper use authority since the same terminal ID and password aremanaged, the state management part 53 stores, on the record identifiedby the terminal ID and the destination name of the terminal 10 aa, theoperating state, the reception date and time when the above-mentionedlogin request information has been received and the IP address of theterminal 10 aa in the terminal management table (see FIG. 11) of theterminal management DB 5003 in a manner of associating them with eachother (step S24). Thereby, in the terminal management table shown inFIG. 11, the operating state “on-line”, the reception date and time“2009.11.10.13:40” and the IP address “1.2.1.3” are associated with theterminal ID “01aa” and are managed.

Then, the communication part 51 of the management system 50 transmitsauthentication result information indicating the result of theauthentication obtained by the terminal authentication part 52 to therequest source terminal (terminal 10 aa), having carried out theabove-mentioned login request, via the communication network 2 (stepS25).

Below, description will be carried out continuously supposing a casewhere the terminal authentication part 52 has determined that theterminal having carried out the above-mentioned login request has theproper use authority. At the terminal 10 aa, when receiving theauthentication result information indicating the result of having beendetermined as a terminal having the proper use authority, thecommunication part 11 transmits destination list request informationindicating to request the destination list to the management system 50via the communication network 2 (step S26). Thereby, the communicationpart 51 of the management system 50 receives the destination listrequest information.

Next, the terminal extraction part 54 of the management system 50searches the destination list management table of the destination listmanagement DB 5004 (see FIG. 12) using the terminal ID “01aa” of therequest source terminal (terminal 10 aa) having carried out the loginrequest as a search key, and reads out and extracts the terminal IDs ascandidates for a destination terminal which can carry out a telephonecall with the request source terminal (terminal 10 aa) (step S27).Further, the terminal extraction part 54 searches the terminalmanagement table (see FIG. 11) of the terminal management DB 5003 usingthe thus-extracted terminal IDs, and reads and extracts the destinationnames corresponding to the terminal IDs. Here, the terminal IDs (“01ab”,“01ba”, “01bb”, . . . ) of destination terminals (10 ab, 10 ba, 10 bb, .. . ) corresponding to the terminal ID “01aa” of the request sourceterminal (terminal 10 aa), and the terminal names (“A company Tokyooffice AB terminal”, “B company Osaka office BA terminal”, . . . ) areextracted.

Next, the communication part 51 of the management system 50 reads thedata of the destination list frame (data of the destination list frame311-1 part shown in FIG. 21) from the non-volatile storage part 5000 viathe storing/reading processing part 59 (step S28), and further,transmits “destination list information (destination list frame,terminal IDs and destination names)” including the destination listframe, the terminal IDs and the destination names thus extracted by theterminal extraction part 54 to the request source terminal (terminal 10aa) (step S29). Thereby, at the request source terminal (terminal 10aa), the communication part 11 receives the destination listinformation, and the storing/reading processing part 19 stores thedestination list information in the volatile storage part 1002 (stepS30).

Thus, according to the embodiment, the respective terminals 10 do notmanage the destination list information but the management system 50manages the destination list information for all the terminals 10 in aunifying manner. Thereby, even in a case where a new terminal 10 comesto be included in the transmission system 1, in a case where a terminal10 of a new type comes to be included instead of an existing terminal 10or in a case where the appearance or such of the destination list frameis to be changed, the management system 50 deals with the matter, andthus, it is possible to eliminate the work of changing the destinationlist being carried out by the terminals 10.

Further, the terminal state obtaining part 55 searches the terminalmanagement table (see FIG. 11) using the terminal IDs (“01ab”, “01ba”and “01bb”, . . . ) of the candidates for a destination terminalextracted by the terminal extraction part 54 as mentioned above assearch keys, reads the respective operating states for theabove-mentioned respective terminal IDs extracted by the terminalextraction part 54, and obtains the respective operating states of theterminals (10 ab, 10 ba, 10 bb, . . . ) (step S31).

Next, the communication part 51 transmits a set of “terminal operatingstate information” (i.e., the state information indicating the operatingstate of a terminal 10) including the terminal ID “01ab” extracted asone of the candidates for a destination terminal by the terminalextraction part 54 in step S27 and the operating state “off-line” of thecorresponding destination terminal (terminal 10 ab) to the requestsource terminal (terminal 10 aa) via the communication network 2 (stepS32). Further, also in step S32, the communication part 51 transmitsanother set of “terminal operating state information” including theterminal ID “01ba” extracted as another of the candidates for adestination terminal by the terminal extraction part 54 in step S27 andthe operating state “on-line (temporarily interrupted)” of thecorresponding destination terminal (terminal 10 ba) to the requestsource terminal (terminal 10 aa) via the communication network 2. In thesame way, in step S32, the communication part 51 transmits respectivesets of “terminal operating state information” for all of the remainingterminals extracted as the candidates for a destination terminal by theterminal extraction part 54 in step S27 to the request source terminal(terminal 10 aa) via the communication network 2, separately.

Next, the storing/reading processing part 19 of the request sourceterminal (terminal 10 aa) stores the respective sets of the terminaloperating state information received from the management system 50 inthe volatile storage part 1002, in sequence (step S33). Thereby, therequest source terminal (terminal 10 aa) can obtain the operating statesof the respective terminals 10 ab, . . . at the current time which arethe candidates for a destination terminal which can carry out atelephone call with the request source terminal (terminal 10 aa).

Next, the destination list creation part 20 of the request sourceterminal (terminal 10 aa) creates a destination list on which the statesof the terminals 10 as the destination candidates are reflected based onthe destination list information and the terminal operating stateinformation stored in the volatile storage part 1002. Further, thedisplay control part 16 controls timing of displaying the destinationlist on the display device 120 shown in FIG. 3 (step S34).

Thus, as shown in FIG. 21, the destination list where the respectivedestination names 311-2 and so forth and the icons 311-3 a and so forthon which the respective sets of the terminal operating state informationare reflected are displayed is displayed on the display device 120 aa.

On the other hand, returning to FIG. 18, the terminal extraction part 54of the management system 50 searches the destination list managementtable of the destination list management DB 5004 (see FIG. 12) using theterminal ID “01aa” of the request source terminal (terminal 10 aa)having carried out the login request as a search key, and extracts theterminal IDs of the other request source terminals which have registeredthe above-mentioned request source terminal (terminal 10 aa) as acandidate for a destination terminal (step S35). In the destination listmanagement table shown in FIG. 12, the terminal IDs of the other requestsource terminals to be thus extracted are “01ab”, “01ba” and “01db”.

Next, the terminal state obtaining part 55 of the management system 50searches the terminal management table of the terminal management DB5002 (see FIG. 11) using the terminal ID “01aa” of the request sourceterminal (terminal 10 aa) having carried out the above-mentioned loginrequest, and obtains the operating state of the request source terminal(terminal 10 aa) having carried out the login request (step S36).

Next, the communication part 51 transmits “terminal state information”including the terminal ID “01aa” of the request source terminal(terminal 10 aa) and the operating state “on-line” obtained in step S36to the terminals (10 ba and 10 db) which have the operating state of“on-line” in the terminal management table of the terminal management DB5003 (see FIG. 11) among the terminals (10 ab, 10 ba and 10 db) havingthe terminal IDs (01ab, 01ba and 01db) extracted in step S35 (stepS37-1, S37-2). It is noted that when the communication part 51 is tothus transmit the terminal state information to the terminals 10 ba and10 db, the communication part 51 reads the IP addresses of theseterminals managed in the terminal management table shown in FIG. 11based on the respective terminal IDs (“01ba” and “01db”). Thereby, it ispossible to inform the respective destination terminals (terminals 10 baand 10 db) which can carry out a telephone call with the request sourceterminal (terminal 10 aa) having carried out the login request as thedestination, of the terminal ID “01aa” and the operating state “on-line”of the request source terminal (terminal 10 aa) having carried out theabove-mentioned login request.

On the other hand, also at each of the other terminals 10, the same asthe above-mentioned step S21, when the user turns on the power supplyswitch 109 shown in FIG. 3, the operation input reception part 12 shownin FIG. 5 receives the power supply turning on operation, and theprocesses the same as those of steps S22 through S38-1 and S38-2mentioned above are carried out. Therefore, the description thereforwill be omitted.

Next, with reference to FIG. 19, a process when a terminal 10 startscommunication with another terminal 10 will be described. It is notedthat in FIG. 19, the various sorts of management information aretransmitted and received wholly by the management information session“sei”. Further, according to the embodiment, the request source terminal(terminal 10 aa) can request to start communication by selecting atleast one of the terminals 10 having the operating state “on-line”according to the state information (terminal operating stateinformation) received in the above-mentioned step S32 from among theterminals 10 as the candidates for a destination, or the own terminal(terminal 10 aa). It is noted that to select the own terminal (terminal10 aa) means that the request source terminal (terminal 10 aa) requeststo connect only the own terminal to the relay apparatus 30. Below, aprocess of requesting to start communication will be described.

First, when the user of the request source terminal (terminal 10 aa)presses the operating button 108 shown in FIG. 3 to select a destinationterminal (supposing the terminal 10 db, for example), the operationinput reception part 12 shown in FIG. 5 receives the request forstarting a telephone call with the destination terminal (terminal 10 db)(step S41). Then, the communication part 11 of the request sourceterminal 10 aa transmits start request information including theterminal ID “01aa” of the terminal 10 aa and the terminal ID “01db” ofthe thus-selected destination terminal (terminal 10 db) and indicatingan intention to start a telephone call, to the management system 50(step S42). Thereby, the communication part 51 of the management part 50receives the start request information, and can obtain the IP address ofthe request source terminal (terminal 10 aa) (transmission source).

Then, the state management part 53 changes the field areas of operatingstate on the records of the above-mentioned terminal ID “01aa” andterminal ID “01db”, respectively, in the terminal management DB 5003(see FIG. 11), into “on telephone call”, based on the terminal ID “01aa”of the request source terminal (terminal 10 aa) and the terminal ID“01db” of the destination terminal (terminal 10 db) included in thestart request information (step S43). It is noted that in this state,although a telephone call has not yet been started between the requestsource terminal (terminal 10 aa) and the destination terminal (terminal10 db), the request source terminal (terminal 10 aa) and the destinationterminal (terminal 10 db) thus enter the state of “on telephone call”.Therefore, when another terminal intends to carry out a telephone callwith the request source terminal (terminal 10 aa) or the destinationterminal (terminal 10 db), a notification sound or display indicatingthe “on telephone call” state is output.

Next, a process of carrying out a session for selecting a relayapparatus 30 will be described. First, the session ID generating part 56a generates a session ID “se1” for identifying a session (image andvoice data session “sed”) for carrying out communication with eachterminal 10 requested by the request source terminal (terminal 10 aa)(step S44).

Then, the relay apparatus selection part 56 selects a relay apparatus 30for relaying a telephone call between the request source terminal(terminal 10 aa) and the destination terminal (terminal 10 db) based onthe relay apparatus management DB 5001 (step S45). A detailed process ofselecting a relay apparatus 30 will now be described with reference toFIG. 20.

First, the destination determination part 56 b determines whether theterminal ID of the destination terminal and the terminal ID of therequest source terminal (terminal 10 aa) included in the start requestinformation sent from the request source terminal (terminal 10 aa) arethe same (i.e., whether the own terminal has been selected as thedestination) (step S45-1). In a case where the terminal ID of thedestination terminal is the same as the terminal ID of the requestsource terminal, the selection part 56 e selects the relay apparatus 30abcd (common relay apparatus) (step S45-4). This is because it ispreferable to select a relay apparatus 30 to which any terminal canconnect since a communication network with which a terminal which willparticipate in the session thereafter or an area where a terminal whichwill participate in the session thereafter is connected to thecommunication network 2 is not known.

In a case where the terminal ID of the destination terminal is not thesame as the terminal ID of the request source terminal (step S45-1 NO),the attribute extraction part 56 c searches the attribute managementtable of the attribute management DB 5008 (see FIG. 15) based on theterminal IDs of the request source terminal (terminal 10 aa) and thedestination terminal (terminal 10 db), and extracts the correspondingintranet relay apparatus IDs. Then, the attribute determination part 56d determines whether the extracted intranet relay apparatus IDs are thesame (whether the request source terminal and the destination terminalcan use the same intranet relay apparatus 30) (step S45-2). In a casewhere the extracted intranet relay apparatus IDs are the same (stepS45-2 YES), the selection part 56 e selects the relay apparatus 30(intranet relay apparatus) identified by the extracted intranet relayapparatus ID (step S45-6). Thereby, the selected relay apparatus 30 andall the terminals participating in the session will be connected to thesame intranet. Thus, the communication paths are shortened, and thecommunication rates are improved. Also, content data to be communicatedthat does not need to clear any firewall, and security is improved.

It is noted that even in a case where the respective intranet relayapparatus IDs extracted by the attribute extraction part 56 c are thesame, the process starting from step S45-2 NO may be carried outdepending on a state of the relay apparatus identified by this intranetrelay apparatus ID. In this case, the management system 50 searches therelay apparatus management table (see FIG. 9) of the non-volatilestorage part 5000 using the storing/reading processing part 59 based onthe relay apparatus ID of the intranet relay apparatus, and extracts thecorresponding operating state. In a case where the extracted operatingstate is “off-line”, the management system 50 proceeds to the processstarting from step S45-2 NO. Further, in another example, the managementsystem 50 searches the relay apparatus management table (see FIG. 9) viathe storing/reading processing part 59 based on the relay apparatus IDof the intranet relay apparatus, and extracts the corresponding numberof ports used and number of ports usable. Then, in a case where anoperating rate calculated by the extracted number of ports used andnumber of ports usable is larger than a certain value, the managementsystem 50 proceeds to the process starting from step S45-2 NO.

In a case where the intranet relay apparatus IDs extracted by theattribute extraction part 56 c are not the same (step S45-2 NO), theattribute extraction part 56 c searches the attribute management tableof the attribute management DB 5008 (see FIG. 15) based on the terminalIDs of the request source terminal (terminal 10 aa) and the destinationterminal (terminal 10 db), and extracts the corresponding segment relayapparatus IDs. In a case where the extracted segment relay apparatus IDsare the same (step S45-3 YES), the selection part 56 e selects the relayapparatus 30 (segment relay apparatus) identified by the extractedsegment relay apparatus ID (step S45-5). Thereby, the selected relayapparatus 30 and all the terminals participating in the session will beconnected to the communication network 2 from the same segment. Thus,the communication paths are shortened, and the communication rates areimproved.

It is noted that even in a case where the respective segment relayapparatus IDs extracted by the attribute extraction part 56 c are thesame, the process starting from step S45-3 NO may be carried outdepending on a state of the relay apparatus identified by this segmentrelay apparatus ID. In this case, the management system 50 searches therelay apparatus management table (see FIG. 9) of the non-volatilestorage part 5000 using the storing/reading processing part 59 based onthe relay apparatus ID of the segment relay apparatus, and extracts thecorresponding operating state. In a case where the extracted operatingstate is “off-line”, the management system 50 proceeds to the processstarting from step S45-3 NO. Further, in another example, the managementsystem 50 searches the relay apparatus management table (see FIG. 9) viathe storing/reading processing part 59 based on the relay apparatus IDof the segment relay apparatus, and extracts the corresponding number ofports used and number of ports usable. Then, in a case where anoperating rate calculated by the extracted number of ports used andnumber of ports usable is larger than a certain value, the managementsystem 50 proceeds to the process starting from step S45-3 NO.

In a case where the segment relay apparatus IDs extracted by theattribute extraction part 56 c are not the same (step S45-3 NO), theselection part 56 e selects the relay apparatus 30 abcd (common relayapparatus) (step S45-4). This is because the respective terminalsparticipating in the session cannot use the relay apparatus 30 in thesame communication network or the relay apparatus 30 in the samesegment.

When the process of selecting the relay apparatus 30 is thus completed,the session management part 57 stores, in the session management table(see FIG. 13) of the session management DB 5005 of the non-volatilestorage part 5000, the session ID “se1” generated in step S44, theterminal ID of the request source terminal (terminal 10 aa), theterminal ID of the destination terminal (terminal 10 db) and the relayapparatus ID of the selected relay apparatus, and manages them (stepS46).

Next, the communication part 51 shown in FIG. 5 transmits, to therequest source terminal (terminal 10 aa) via the communication network2, the session ID generated by the session ID generation part 56 a andrelay apparatus connection information used for connecting to the relayapparatus selected by the selection part 56 e (step S48). The relayapparatus connection information may include the IP address,authentication information, port numbers and so forth of the relayapparatus 30. Thereby, the request source terminal (terminal 10 aa) canobtain the relay apparatus connection information used for connecting tothe relay apparatus 30 used for relaying image and voice data inexecution of the session of the session ID “se1”.

Next, the communication part 51 transmits, to the destination terminal(terminal 10 db), the terminal ID of the request source terminal(terminal 10 aa), start request information including the session ID“se1”, the relay apparatus connection information used for connecting tothe relay apparatus 30 and the IP address of the management system 50(step S48). Thereby, the communication part 11 of the terminal 10 dbreceives the above-mentioned start request information, and obtains therelay apparatus connection information used for connecting to the relayapparatus 30 used for relaying content data and the IP address “1.1.1.2”of the management system 50 (transmission source).

Next, the communication part 51 of the management system 50 transmits,to the selected relay apparatus 30 via the communication network 2,relay start request information indicating a request to start relaying(step S49). The relay start request information includes the respectiveIP addresses of the request source terminal (terminal 10 aa) and thedestination terminal (terminal 10 db) for which content data is relayed.Thereby, the relay apparatus 30 establishes a session (image and voicedata session “sed”) for carrying out a telephone call with three sets ofimage data of high resolution, medium resolution and low resolution andvoice data (step S50). Thereby, the terminals 10 can start a TVconference.

Next, using FIG. 22, a process of another terminal 10 participating inthe telephone call session (image and voice data session “sed”) afterthe telephone call session is established between the request sourceterminal (terminal 10 aa) and the destination terminal (terminal 10 db)will be described. FIG. 22 is a sequence diagram showing a process ofrequesting participation in the image and voice data session “sed”. Itis noted that in FIG. 22, a process is shown where all of the varioussorts of management information are transmitted and received by themanagement information session “sei”.

First, as a result of the user of the request source terminal (terminal10 aa) pressing the operating button 108 shown in FIG. 3, an inputindicating another terminal 10 to be invited to the image and voice datasession “sed” is received (step S101). Then, the communication part 11of the terminal 10 aa transmits session ID notification requestinformation, including the terminal ID of the terminal 10 aa, theterminal ID of the other terminal 10 and the session ID, and requestingto notify the other terminal 10 of these items of information, to themanagement system 50 (step S102). When receiving the session IDnotification request information, the communication part 51 of themanagement system 50 transmits session ID notification information,including the terminal ID of the request source terminal (terminal 10aa) and the session ID, to the other terminal 10 (step S103).

When receiving the above-mentioned session ID notification information,the other terminal 10 receives an intention of the user of the otherterminal 10 to participate in the image and voice data session “sed”(step S104). Here, as a result of the user of the other terminal 10pressing the operating button 108 shown in FIG. 3, the user's intentionto request to participate in the image and voice data session “sed” isreceived. Thereby, the communication part 11 of the other terminal 10transmits, to the management system 50, session participation requestinformation including the terminal ID of the other terminal 10 and thesession ID (step S105).

Next, the management system 50 carries out a process of selecting arelay apparatus 30 (step S106). The process of selecting a relayapparatus 30 will be described in detail using FIG. 23. FIG. 23 is aflowchart showing a process of selecting a relay apparatus 30. First,the session management part 57 of the management system 50 searches thesession management table (see FIG. 13) of the session management DB 5005using the session ID included in the session participation requestinformation as a key, and extracts the relay apparatus ID (step S106-1).Next, the attribute extraction part 56 c searches the attributemanagement table (see FIG. 15) of the attribute management DB 5008 basedon the terminal ID of the other terminal 10, and extracts thecorresponding intranet relay apparatus ID and segment relay apparatusID.

Next, the attribute determination part 56 d determines whether the otherterminal 10 can use the relay apparatus 30 identified by the relayapparatus ID extracted by the session management part 57 in step S106-1can be used (step S106-2). Specifically, in a case where the relayapparatus ID extracted by the session management part 57 in step S106-1is the relay apparatus ID of the common relay apparatus 30 abcd, theattribute determination part 56 d determines that the relay apparatus 30identified by the relay apparatus ID extracted by the session managementpart 57 in step S106-1 can be used. In a case where the relay apparatusID extracted by the session management part 57 is not the relayapparatus ID of the common relay apparatus 30 abcd, and is consistentwith any of the relay apparatus IDs extracted by the attributeextraction part 56 c in step S106-1, the attribute determination part 56d determines that the relay apparatus 30 identified by the relayapparatus ID extracted by the session management part 57 in step S106-1can be used. On the other hand, in a case where the relay apparatus IDextracted by the session management part 57 in step S106-1 is not therelay apparatus ID of the common relay apparatus 30 abcd, and isconsistent with none of the relay apparatus IDs extracted by theattribute extraction part 56 c in step S106-1, the attributedetermination part 56 d determines that the relay apparatus 30identified by the relay apparatus ID extracted by the session managementpart 57 in step S106-1 cannot be used.

In the case where it has been determined that the relay apparatus 30identified by the relay apparatus ID extracted by the session managementpart 57 in step S106-1 can be used (step S106-2 YES), the selection part56 e selects the relay apparatus 30 which is being used for the imageand voice data session “sed” and extracted by the session managementpart 57 in step S106-1 (step S106-4). In a case where it has beendetermined that the relay apparatus 30 identified by the relay apparatusID extracted by the session management part 57 in step S106-1 cannot beused (step S106-2 NO), the selection part 56 e does not select the relayapparatus 30 which is being used for the image and voice data session“sed” and extracted by the session management part 57 in step S106-1(step S106-3). It is noted that in the case where it has been determinedthat the relay apparatus 30 identified by the relay apparatus IDextracted by the session management part 57 in step S106-1 cannot beused (step S106-2 NO), the selection part 56 e may newly select thecommon relay apparatus 30 abcd. Below, a process to be carried outthereafter will be described supposing the case where the selection part56 e has selected the relay apparatus 30 which is being used for theimage and voice data session “sed” and extracted by the sessionmanagement part 57 in step S106-1.

When the selection of the relay apparatus 30 is thus completed, thesession management part 57 stores, in the session management table (seeFIG. 13) of the session management DB 5005 of the non-volatile storagepart 5000, the session ID included in the session participation requestinformation, the terminal ID of the request source terminal (terminal 10aa), the terminal ID of the destination terminal (terminal 10 db), theterminal ID of the other terminal 10 and the relay apparatus ID of theselected relay apparatus 30, and manages them (step S107).

Next, the state management part 53 of the management system 50 changesthe field area of operating state on the record including the terminalID of the other terminal 10 in the terminal management table (see FIG.11) of the terminal management DB 5003, based on the terminal ID of theother terminal 10 included in the session participation requestinformation, into “on telephone call” (step S108).

Next, the communication part 51 of the management system 50 transmits aparticipation notification including the terminal ID of the otherterminal 10 participating in the image and voice data session “sed” andthe session ID to the request source terminal (terminal 10 aa) and thedestination terminal (terminal 10 db) which have already started theimage and voice data session “sed” (steps S109-1, S109-2). Thereby, therequest source terminal (terminal 10 aa) and the destination terminal(terminal 10 db) can determine that the other terminal 10 participatesin the image and voice data session “sed”. Further, the communicationpart 51 of the management system 50 transmits participation permissionnotification including the session ID for participating in the image andvoice data session “sed” and the relay apparatus connection informationused for connecting with the relay apparatus 30 to the other terminal 10which starts the image and voice data session “sed” (step S110).Thereby, the other terminal 10 determines that participation in theimage and voice data session “sed” has been permitted, and also, canconnect with the relay apparatus 30. When receiving the participationpermission notification, the communication part 11 of the other terminal10 transmits, to the relay apparatus 30, the session ID and the relayapparatus connection information (step S110), and connects with therelay apparatus 30. Thereby, the other terminal 10 can participate inthe image and voice data session “sed”.

Next, with reference to FIGS. 5 and 24, a process of transmitting imagedata and voice data between the request source terminal (terminal 10 aa)and the destination terminal (terminal 10 db) for the purpose ofcarrying out a telephone call of a TV conference will be described. Itis supposed that a relay apparatus which relays image data and voicedata between these terminals is the relay apparatus 30 abcd. It is notedthat since processes of transmission and reception of image data andvoice data, detection of a delay time described later and so forth areidentical between transmission of image data and voice data in onedirection from the terminal 10 aa to the terminal 10 db and transmissionof image data and voice data in the reverse direction from the terminal10 db to the terminal 10 aa, description will be carried out only forthe communication in the one direction and description for thecommunication in the reverse direction will be omitted.

First, the request source terminal (terminal 10 aa) transmits image dataof an object photographed by the photographing part 14 and voice data ofvoice audio input by the voice input part 15 a to the relay apparatus 30abcd via the communication network 2 from the communication part 11through the image and voice data session “sed” (step S81). It is notedthat in this case, first, image data of high image quality including thethree resolutions of the low resolution, the medium resolution and thehigh resolution, and the voice data are transmitted. Thus, the relayapparatus 30 abcd receives the image data of the three resolutions andthe voice data via the communication part 31. Then, the data qualitydetermination part 33 searches the change quality management table (seeFIG. 7) using the IP address “1.3.2.4” of the destination terminal(terminal 10 db), extracts the corresponding image quality of image datato relay, and thus, determines the image quality of image data to relay(step S82). In this case, supposing that the thus-determined imagequality of image data is “high image quality”, it is the same as theimage quality of the image data received via the communication part 31.Therefore, the relay apparatus 30 abcd transfers the image data of theimage quality as it is and the voice data of the voice quality as it isto the destination terminal (terminal 10 db) through the image and voicedata session “sed” (step S83). Thus, the destination terminal (terminal10 db) receives via the communication part 11 the image data of highimage quality including the three resolutions of the low resolution,medium resolution and high resolution, and the voice data. Then, thedisplay control part 16 of the destination terminal (terminal 10 db) candisplay an image based on the image data on the display device 120, andthe voice output part 15 b can output the voice audio based on the voicedata.

Next, the delay detection part 18 of the terminal 10 db detects thedelay time of reception of the image data received via the communicationpart 11 at certain time intervals (for example, once a second) (stepS84). It is noted that description will be carried out below supposing acase where the thus-detected delay time is 200 ms. The detection of thedelay time of reception of image data may be carried out in such amanner that, for example, information indicating transmission date andtime when the image data is transmitted from the transmission sourceterminal is attached to the image data, and the transmission destinationterminal calculates the delay time based on the difference between thetransmission and reception of the received image data, using theinformation indicating transmission date and time attached to thereceived image data and reception date and time when the received imagedata has been received in the transmission destination terminal.

The communication part 11 of the destination terminal (terminal 10 db)transmits delay information indicating the delay time “200 ms” to themanagement system 50 via the communication network 2 through themanagement information session “sei” (step S85). Thereby, the managementsystem 50 obtains the delay time and also obtains the IP address“1.3.2.4” of the terminal 10 db that is the transmission source of thedelay information.

Next, the delay time management part 60 of the management system 50searches the terminal management table (see FIG. 11) using the IPaddress “1.3.2.4” of the above-mentioned destination terminal (terminal10 db) as a search key, extracts the corresponding terminal ID “01db”,stores the delay time “200 ms” indicated by the above-mentioned delayinformation at the field area of delay time on the record of theabove-mentioned terminal ID “01db” in the session management table ofthe session management DB 5005 (see FIG. 13), and manages it (step S86).

Next, the quality determination part 58 searches the quality managementDB 5007 (see FIG. 14) using the above-mentioned delay time “200 ms” as asearch key, extracts the corresponding image quality “medium imagequality” of image data, and thus determines the image quality to be“medium image quality” (step S87).

Next, the communication part 51 obtains the relay apparatus ID “111abcd”associated with the above-mentioned terminal ID “01db” in the sessionmanagement table of the session management DB (see FIG. 13), searchesthe relay apparatus management table (see FIG. 9) using the relayapparatus ID “111abcd” as a search key, and extracts the IP address“1.1.1.3” of the corresponding relay apparatus 30 abcd (step S88). Then,the communication part 51 transmits quality information indicating theimage quality “medium image quality” determined in step S87 to the relayapparatus 30 abcd via the communication network 2 through the managementinformation session “sei” (step S89). The quality information includesthe IP address “1.3.2.4” of the destination terminal (terminal 10 db)used as the search key in step S86. Thereby, the change qualitymanagement part 34 in the relay apparatus 30 abcd stores the IP address“1.3.2.4” of the terminal 10 (here, the terminal 10 db) as thetransmission destination and the image quality “medium image quality” ofimage data to be relayed, in the change quality management table (seeFIG. 7) in a manner of associating them with one another, and managesthem (step S90).

Next, the terminal 10 aa continuously transmits image data of high imagequality including the three resolutions of the low resolution, mediumresolution and high resolution and voice data to the relay apparatus 30abcd through the image and voice data session “sed”, the same as stepS81 mentioned above (step S91). Then, the same as step S82 mentionedabove, the data quality determination part 33 of the relay apparatus 30abcd searches the change quality management table (see FIG. 7) using theIP address “1.3.2.4” of the destination terminal (terminal 10 db) as asearch key, extracts the corresponding image quality “medium imagequality” to relay, and thus determines the quality of an image of imagedata to relay (step S92). In this example, the determined image qualityof image data is “medium image quality” which is lower than the imagequality “high image quality” of the image data received via thecommunication part 31. Therefore, the data quality changing part 35reduces the image quality of the image data from “high image quality” to“medium image quality”, and thus changes the quality of the image of theimage data (step S93). Then, the communication part 31 transmits theimage data for which the image quality has been thus changed to “mediumimage quality” and the voice data for which the voice quality has notbeen changed, to the terminal 10 db via the communication network 2through the image and voice data session “sed” (step S94). Thus, in thecase where the delay in reception occurs in the destination terminal(terminal 10 db) that receives the image data, the relay apparatus 30abcd changes (reduces) the quality of the image to reduce the delay, andthus, it is possible to prevent the persons participating in the TVconference from feeling that something is wrong.

Main Advantageous Effects of Embodiment

As described above, according to the embodiment, in a case of havingdetermined that plural terminals have the same first attributes, themanagement system 50 selects a first relay apparatus. In a case ofhaving determined that the plural terminals do not have the same firstattributes, the management system 50 selects a second relay apparatus ina case of having determined that the plural terminals have the samesecond attributes. In a case of having determined that the pluralterminals do not have the same first attributes, the management system50 selects a third relay apparatus in a case of having determined thatthe plural terminals do not have the same second attributes. Thereby,depending on the plural independent attributes of each of the pluralterminals participating in a conference, the management apparatus 30 canselect an optimum relay apparatus.

Further, according to the embodiment, the management system 50 has theattribute management DB 5008 in which terminal identificationinformation used for identifying terminals 10, first attributeinformation indicating the first attributes of the terminals 10 andsecond attribute information indicating the second attributes of theterminals 10 are associated and managed. Thereby, the management system50 can easily determine whether plural terminals 10 have the same firstattributes and whether the plural terminals 10 have the same secondattributes.

Further, according to the embodiment, the first attribute may be anattribute concerning the communication networks (intranets, i.e., partsof the communication network 2) to which the terminals 10 are connected,respectively, and the second attribute may be an attribute concerningthe areas in which the terminals 10 exist, respectively. Thereby, themanagement system 50 can select a relay apparatus 30 depending on theattributes concerning the communication networks (parts of thecommunication network 2) to which respective terminals 10 participatingin a conference are connected, the areas in which the respectiveterminals 10 are connected with the communication network 2, or such.

Further, according to the embodiment, an intranet relay apparatusbelongs to an intranet the same as that of a terminal 10, and a segmentrelay apparatus is installed at a segment the same as that of a terminal10. In this case, when all the terminals 10 participating in aconference are connected with the intranet, the management system 50selects the intranet relay apparatus. Thereby, the communication pathsare shortened, and the communication rates are improved. Also, contentdata to be communicated does not need to clear any firewall, andsecurity is improved. When all the terminals 10 participating in aconference exist in the same area, the management system 50 selects thesegment relay apparatus. Thereby, the communication paths are shortened,and the communication rates are improved.

Further, according to the embodiment, the first relay apparatustransmits first operating information indicating the operating state ofthe first relay apparatus to the management system 50, and the secondrelay apparatus transmits second operating information indicating theoperating state of the second relay apparatus to the management system50. Thereby, the management system 50 can select any one of the firstand second relay apparatuses based on the respective operating states.

Further, according to the embodiment, the first relay apparatustransmits first port information indicating the states of the ports ofthe first relay apparatus to be used for communication with the terminal10 to the management system 50, and the second relay apparatus transmitssecond port information indicating the states of the ports of the secondrelay apparatus to be used for communication with the terminal 10 to themanagement system 50. Thereby, the management system 50 can select anyone of the first and second relay apparatuses based on the obtainedstates of the ports of the first and second relay apparatuses.

Further, according to the embodiment, the first relay apparatus carriesout secure communication with the management system 50. Thereby, theoperating information and the port information of the first relayapparatus can be safely transmitted to the management system 50.

Supplement to Embodiment

According to the embodiment, the attribute extraction part 56 c searchesthe attribute management table of the attribute management DB 5008 basedon the terminal IDs of the request source terminal (terminal 10 aa) andthe destination terminal (terminal 10 db) and extracts the correspondingattributes. However, it is not necessary to be limited to this method.It is also possible that when the terminal 10 aa and the terminal 10 dbconnect to the management system 50, the respective terminals transmitmessages including the attributes of the respective terminals obtainedat a time of the connections and the attribute extraction part 56 cextracts the attributes included in the messages. Thereby, it ispossible to obtain an advantageous effect of being able to select arelay apparatus 30 based on the attributes of the respective terminalsobtained at a time of the connections.

It is noted that each of the management system 50 and the programproviding system 90 in the embodiment may be realized by a singlecomputer, or may be realized by plural computers where respective parts(or functions) are divided and are freely allocated to the pluralcomputers. Further, in a case where the program providing system 90 isrealized by a single computer, a program to be transmitted by theprogram providing system 90 may be transmitted as having been dividedinto plural modules, or may be transmitted as not having been dividedinto plural modules. Further, in a case where the program providingsystem 90 is realized by plural computers, divided plural modules may betransmitted by the plural computers, respectively.

Further, recording media storing the program for the terminals 10, theprogram for the relay apparatuses 30 and the program for transmissionmanagement, the HD 204 storing these programs, and the program providingsystem 90 including this HD 204 are used as program products in a casewhere the program for the terminals 10, the program for the relayapparatuses 30 and the program for transmission management are providedto users or such in the home country or aboard.

Further, in the embodiment, quality of image data is managed inparticular using resolution of an image of image data as one example ofquality of an image of image data relayed by the relay apparatus 30,using the change quality management table shown in FIG. 7 and thequality management table shown in FIG. 14. However, quality of data isnot limited thereto, and as other examples of quality of data, data maybe managed in particular using a depth (for example, color depth) ofimage quality of image data, a sampling frequency in voice of voicedata, a bit length in voice of voice data, or such.

Further, in FIGS. 9, 11 and 13, the reception dates and times aremanaged. However, it is not necessary to be limited thereto, and it maybe sufficient that at least the reception times from among the receptiondates and times are managed.

Further, according to the embodiment, the IP addresses of relayapparatuses 30 in FIG. 9, and the IP addresses of terminals 10 in FIG.11 are managed. However, it is not necessary to be limited to thismethod, and as long as relay apparatus identification information foridentifying a relay apparatus 30 in the communication network 2 orterminal identification information for identifying a terminal 10 in thecommunication network 2 is used, a FQDN (Fully Qualified Domain Name)thereof may be managed. In this case, the IP address corresponding tothe FQDN will be obtained from a well-known DNS (Domain Name System)server. It is noted that “relay apparatus identification information foridentifying a relay apparatus 30 in the communication network 2” mayalso be expressed as “relay apparatus connecting destination informationindicating a connecting destination for a relay apparatus 30 in thecommunication network 2” or “relay apparatus destination informationindicating a destination for a relay apparatus 30 in the communicationnetwork 2”. Similarly, “terminal identification information foridentifying a terminal 10 in the communication network 2” may also beexpressed as “terminal connecting destination information indicating aconnecting destination for a terminal 10 in the communication network 2”or “terminal destination information indicating a destination for aterminal 10 in the communication network 2”.

According to the embodiment, the term “TV conference” is used as a termwhich may be replaced by “video conference”.

Further, in the embodiment, as an example of the transmission system 1,a case of a TV conference system has been described. However, it is notnecessary to be limited thereto, and an example of the transmissionsystem 1 may be a telephone system for IP (Internet Protocol) telephone,Internet telephone, or such. Further, the transmission system 1 may bean automotive navigation system. In this case, for example, one of theterminals 10 corresponds to an automotive navigation apparatus mountedin one automobile, and another of the terminals 10 corresponds to amanagement terminal or a management server in a management center whichmanages the automotive navigation system, or an automotive navigationapparatus mounted in another automobile. Further, the transmissionsystem 1 may be a voice conference system, or a PC (Personal Computer)screen sharing system.

Further, the transmission system 1 may be a communication system forcellular phones. In this case, the terminals 10 correspond to cellularphones. FIG. 25 shows an example of displaying a destination list 1011-1in this case (corresponding to the destination list shown in FIG. 21 inthe above-described embodiment). The destination list 1011-1 includesicons 1011-3 (corresponding to the icons 311-3 a, 311-3 b and 311-3 cand so forth in FIG. 21) indicating the states for respectivedestination names 1011-2 (“ABE REIJI”, “INOUE ICHIRO”, . . . ) and therespective destination names 1011-2 (corresponding to the destinationname 311-2 and so forth in FIG. 21). The terminal 10 as a cellular phoneincludes a body 10-1 of the cellular phone, a menu screen page displaybutton 10-2 provided on the body 10-1, a display part 10-3 provided onthe body 10-1, a microphone 10-4 provided on a bottom part of the body10-1, and a speaker 10-5 provided on the body 10-1. Thereamong, the“menu screen page display button” 10-2 is a button for displaying a menuscreen page (not shown) which displays icons showing variousapplications. The display part 10-3 includes a touch panel, and as aresult of the user selecting a destination name from the destinationlist displayed as shown in FIG. 25, it is possible to carry out atelephone call with another cellular phone of another user.

Further, in the embodiment, as one example of content data, image dataas sight data and voice data as hearing data have been described.However, it is not necessary to be limited thereto, and others of thefive senses may be used instead. An example of content data may be touchdata. In this case, a feeling occurring when a user touches something onthe side of one of the terminals is transmitted to the side of anotherof the terminals. Further, content data may be smell data. In this case,a smell (or odor) obtained on the side of one of the terminals 10 istransmitted to the side of another of the terminals 10. Further, may besufficient that content data is at least any one of image data, voicedata, touch data and, smell data.

Further, in the embodiment, the case where the TV conference isconducted by using the transmission system 1 has been described.However, it is not necessary to be limited thereto. The transmissionsystem 1 may be used for a meeting, a common conversation between familymembers, friends or such, or may be used for submitting information inone direction.

Although this invention has been described in detail with reference tocertain embodiments, variations and modifications exist within the scopeand spirit of the invention as described and defined in the followingclaims.

The present patent application is based on Japanese Priority ApplicationNo. 2010-267699 filed Nov. 30, 2010 and Japanese Priority ApplicationNo. 2011-192542 filed Sep. 5, 2011, the entire contents of which arehereby incorporated by reference.

The invention claimed is:
 1. A transmission management system which,when content data is communicated among plural transmission terminalsvia a communication network, selects a relay apparatus which relays thecontent data, comprising: a memory configured to store transmissionterminal identification information for identifying the transmissionterminals, first attribute information indicating first attributes ofthe transmission terminals, and second attribute information indicatingsecond attributes of the transmission terminals in a manner ofassociating them with each other; a processing circuitry configured todetermine whether the first attributes of respective plural transmissionterminals are the same based on the first attributes corresponding tothe transmission terminal identification information for identifying therespective plural transmission terminals stored in the memory; determinewhether the second attributes of the respective plural transmissionterminals are the same based on the second attributes corresponding tothe transmission terminal identification information for identifying therespective plural transmission terminals stored in the memory; andselect a first relay apparatus when it is determined that the firstattributes are the same, select a second relay apparatus when it isdetermined that the first attributes are not the same but the secondattributes are the same, and select a third relay apparatus when it isdetermined that the first attributes are not the same and the secondattributes are not the same; and wherein the first attribute is anattribute concerning respective parts of the communication network withwhich the transmission terminals are connected, and the second attributeis an attribute concerning respective areas where the transmissionterminals are connected with the communication network.
 2. Atransmission system comprising: plural transmission terminals configuredto communicate content data via a communication network; a relayapparatus configured to relay the content data; and the transmissionmanagement system claimed in claim
 1. 3. The transmission system asclaimed in claim 2, wherein: the first relay apparatus has the firstattribute the same as those of the respective plural transmissionterminals; and the second relay apparatus has the second attribute thesame as those of the respective plural transmission terminals.
 4. Thetransmission system as claimed in claim 2, wherein the first relayapparatus transmits first operating information indicating an operatingstate of the first relay apparatus; the second relay apparatus transmitssecond operating information indicating an operating state of the secondrelay apparatus; and the processing circuitry determines whether toselect the first relay apparatus based on the first operatinginformation and determines whether to select the second relay apparatusbased on the second operating information.
 5. The transmission system asclaimed in claim 2, wherein the first relay apparatus transmits firstport information indicating a state of ports of the first relayapparatus used for communication with the transmission terminals; thesecond relay apparatus transmits second port information indicating astate of ports of the second relay apparatus used for communication withthe transmission terminals; and the processing circuitry determineswhether to select the first relay apparatus based on the first portinformation and determines whether to select the second relay apparatusbased on the second port information.
 6. The transmission system asclaimed in claim 4, wherein the first relay apparatus carries out securecommunication with the transmission management system.
 7. Thetransmission system as claimed in claim 5, wherein the first relayapparatus carries out secure communication with the transmissionmanagement system.
 8. A non-transitory computer-readable medium storinga program for a transmission management system which, when content datais communicated among plural transmission terminals via a communicationnetwork, selects a relay apparatus which relays the content data, theprogram when executed by one or plural processors, causes thetransmission management system, having a memory configured to storetransmission terminal identification information for identifying thetransmission terminals, first attribute information indicating firstattributes of the transmission terminals, and second attributeinformation indicating second attributes of the transmission terminalsin a manner of associating them with each other, to perform: determiningwhether the first attributes of respective plural transmission terminalsare the same based on the first attributes corresponding to thetransmission terminal identification information for identifying therespective plural transmission terminals stored in the memory;determining whether the second attributes of the respective pluraltransmission terminals are the same based on the second attributescorresponding to the transmission terminal identification informationfor identifying the respective plural transmission terminals stored inthe memory; and selecting a first relay apparatus when it is determinedthat the first attributes are the same, selecting a second relayapparatus when it is determined that the first attributes are not thesame but the second attributes are the same, and selecting a third relayapparatus when it is determined that the first attributes are not thesame and the second attributes are not the same; and wherein the firstattribute is an attribute concerning respective parts of thecommunication network with which the transmission terminals arcconnected, and the second attribute is an attribute concerningrespective areas where the transmission terminals are connected with thecommunication network.
 9. A method for, when content data iscommunicated among plural transmission terminals via a communicationnetwork, selecting a relay apparatus which relays the content data, themethod comprising: selecting, by a transmission management system havinga memory configured to store transmission terminal identificationinformation for identifying the transmission terminals, first attributeinformation indicating the first attributes of the transmissionterminals, and second attribute information indicating the secondattributes of the transmission terminals in a manner of associating themwith each other; determining whether the first attributes of respectiveplural transmission terminals are the same based on the first attributescorresponding to the transmission terminal identification informationfor identifying the respective plural transmission terminals stored inthe memory; determining whether the second attributes of the respectiveplural transmission terminals are the same based on the secondattributes corresponding to the transmission terminal identificationinformation for identifying the respective plural transmission terminalsstored in the memory; and selecting a first relay apparatus when it isdetermined that the first attributes are the same, selecting a secondrelay apparatus when it is determined that the first attributes are notthe same but the second attributes are the same, and selecting a thirdrelay apparatus when it is determined that the first attributes are notthe same and the second attributes are not the same; and wherein thefirst attribute is an attribute concerning respective parts of thecommunication network with which the transmission terminals areconnected, and the second attribute is an attribute concerningrespective areas where the transmission terminals are connected with thecommunication network.